Neutral Citation Number: [2006] EWHC 2370 (Admin)
Case No: CO3044/2005
IN THE SUPREME COURT OF JUDICATURE
QUEEN'S BENCH DIVISION
DIVISIONAL COURT

Royal Courts of Justice
Strand, London, WC2A 2LL

Date: 29/09/2006

Before :

LORD JUSTICE MOSES
MR JUSTICE OUSELEY
MR JUSTICE WALKER
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Between :

	R (MONDELLY)	Claimant	
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	THE COMMISSIONER OF THE POLICE FOR THE METROPOLIS	Defendant	

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Mr K Starmer QC and Mr H Southey (instructed by Bhatt Murphy, Solicitors) for the Claimant
Mr J Beer (instructed by the Directorate of Legal Services, Metropolitan Police Service), for the Defendant

Hearing dates: 28th July 2006
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Judgment
Lord Justice Moses : 

Background
1.	“Just a spliff, man”, responded Mr Mondelly, when he was arrested by two police officers at his home at 9.30 p.m. on 16 February 2005. He was unfortunate. The two police officers were investigating a burglary but had gone to the wrong address. When they knocked on the front door of Mr Mondelly’s flat, he opened the door and invited them inside. The police officers say that they could smell cannabis. They tried Mr Mondelly’s keys in the door to prove that he lived there. He did live there. The police officers noticed a cannabis cigarette, a grinder, one small cube of cannabis resin and what they believed to be herbal cannabis. They arrested him for allowing his premises to be used for the smoking of cannabis contrary to Section 8 (d) Misuse of Drugs Act 1971. The police officers then searched the premises. One of them left when the local resident who had originally called the police in relation to the suspected burglary came to the flat. 
2.	On the return of that officer, Mr Mondelly was handcuffed and taken to Stoke Newington Police Station. 
3.	Mr Mondelly was later seen at the station by a doctor who, despite the claimant’s history of anxiety and problems with his mental health, was found fit to be detained. 
4.	At 12.45 a.m. Mr Mondelly was allowed out of his cell to speak to a solicitor but complained, about half an hour later, of panic attacks. He was again seen by a doctor and found fit to be interviewed. He saw his solicitor about 3.15 a.m. and was interviewed by the two arresting officers. During the course of the interview, he told the officers that nobody else came to the flat to smoke cannabis. He explained that he did not have much of a social life and friends did not come to the flat to visit. 
5.	Following the interview, it appears that the officers concerned accepted that there was insufficient evidence to charge Mr Mondelly with the offence for which he was arrested, permitting his premises to be used for smoking cannabis. I shall say nothing further about the arrest and the circumstances of his detention. Although, originally, the claimant had sought to bring judicial review proceedings seeking to impugn his arrest and detention, permission was refused. The claimant did not renew his application for permission to challenge the original arrest and the circumstances of his detention before us. He was content to pursue available remedies by way of civil proceedings pursuant to CPR 54, although there was controversy as to whether they should be ordered to continue in the Central London County Court or the Queen’s Bench Division. Lawfulness of the arrest is relevant not only to civil liability but to lawfulness of the retention of the finger prints and DNA samples.
6.	We should say, at this stage, that despite Mr. Starmer QC’s concern, on behalf of the claimant, that transfer to the County Court would cause delay, and that there were substantial issues in relation to retention of samples, we have taken the view that the County Court is well able to deal, expeditiously with all those issues and we have already ordered transfer.
7.	Once the decision had been made not to charge the claimant with the offence under Section 8 (d) of the 1971 Act, a decision was taken which the claimant seeks to impugn in these proceedings. Police Sergeant Collinson, one of the arresting officers and Inspector Barrett, the duty Inspector, discussed whether it was appropriate to administer a caution. They decided, just before 4 a.m., to do so. On Mr. Mondelly’s agreement to accept a caution, it was formerly administered. The record identifies the offence as possession of a Class C drug and records that the claimant was found in possession of a small amount of cannabis. 
8.	Since the reasons for that caution are central to this application, I should set out Inspector Barrett’s account of his reasons, recorded in a statement nearly five months later, on 13th October 2005. He recalls that he was told that Mr Mondelly had admitted in interview that he was in possession of the cannabis and that he was told that Mr Mondelly had a previous caution for possession of cannabis some years before. He took the view that there was enough evidence to charge for the possession of cannabis. He continues: -
“I was aware of the Metropolitan Police policy on arrests for possession of cannabis as embodied in Notice 3/2004 but this policy does not state either that no arrests should be made for possession of cannabis or that, an arrest having been made, it is inappropriate to caution a person found in possession of cannabis. 
The offering of a caution remains a valid case disposal option (see paragraph 5.2 of Notice 3/2004). It would have been inappropriate to “no further action” this matter given the cannabis that had been found at his address, his admission in interview and the fact that he had previous caution for a similar matter from some years earlier. To “no further action” the matter would have been to condone what remains a criminal offence. 
If Mr Mondelly had refused to accept a caution, it would have still been inappropriate to “no further action” the matter. Instead I would have directed that he be held pending advice from the Crown Prosecution service. It was for them rather than for me to decide whether to prosecute. It was not for me to make a decision which would usurp the role of the CPS or had the effect of stating that no crime had been committed. Cannabis remains a controlled drug in Class C and its possession remains an offence.”
9.	The claimant contends that the caution, in the instant case, was administered in breach of relevant police policy which was either ignored or misconstrued by the Inspector. Alternatively, it was Wednesbury irrational to administer the caution in the circumstances of this case.

The “Policies” In Issue

10.	The true nature and effect of what the claimant contends to be police policy requires analysis. But that which forms the basis of what he contends to be a relevant policy must be deduced from a number of documents.  Article 2 of the Misuse of Drugs Act 1971 (Modification (Nº2) Order 2003 (S.I. 2003/3201) re-classified cannabis as a Class C drug on 29th January 2004. It is important to recall that Schedule 1A of the Police and Criminal Evidence Act 1984 (“PACE”), which contains a list of arrestable offences, was amended by Sections 3 (1) and ( 3) of the Criminal Justice Act 2003, so as to add the offence of simple possession of a controlled drug contrary to Section 5 (2), in respect of cannabis or cannabis resin to the list of offences, the very day, 29th January 2004, that cannabis was re-classified as a Class C drug. 
11.	On that day, a Metropolitan Police Service Notice 3/2004 was issued to police officers. When disclosed, by virtue of the Freedom of Information Act, it was described as “Policing of Cannabis as a Class C Drug” following its re-classification from a Class B to a Class C controlled drug. 
12.	The purpose of the new policy was described: - 
“to establish clear guidance and accountability ensuring that the least amount of policing time possible is spent dealing with a drug of lesser classification. It will ensure the integrity of offenders and police officers and allow the identification of an offence, seizure of a lawful substance and case disposal in situ without the need to arrest or recourse to a supervisor”
13.	Under the heading “Scope”, the policy was said to complement national guidance issued by the Association of Chief Police Officers and continues:-
“It does not affect offences of production, supply or possession with intent to supply cannabis. 
It will apply to any adult offenders found in possession (constructive or otherwise) of cannabis, where the officer is satisfied, that the cannabis is intended for that person’s use. The standard operating procedure identifies aggravating factors where an officer may consider arrest. The Standard Operating Procedures (SOP) also provide specific guidance for young persons found in possession of cannabis.”
14.	The policy statement was as follows:-
“A police officer, finding a person in possession of cannabis, who is satisfied that the drug is intended for that person’s own use should not arrest the offender unless aggravating factors apply. The drug must be seized but no further action should be taken in respect of the offence, other than administrative procedures identified in the SOP. Young persons should be arrested to allow formal disposal through the youth justice process.”
15.	It is important to note that under the rubric “benefit”, the Notice continues:-
“This policy is not intended to interfere with the discretion of a police officer, but to provide direction and focus towards governmental and policing priorities. It formalises practices identified in Lambeth, where “informal disposal of cannabis” took place. This activity had implications for the integrity of the officer and offender. This practice was recognised by academic research. 
This policy provides a framework to allow seizure of cannabis without arrest, protecting the officer and offender, thereby improving morale and public confidence. This approach to cannabis will also remove a source of friction between police and young people. It will reduce the amount of time devoted to policing the possession of a drug which is undoubtedly harmful to individual health, but does not cause damage or danger to health or to the community on the scale of crack cocaine, cocaine, or heroin.”
16.	The policy thus far cited, was available on the internet. The Standard Operating Procedures were not, although they were disclosed for the purposes of this case. The Standard Operating Procedures put in to practical effect the parts of the Notice I have already cited. 
“1.2 However, the MPS priority is to disrupt the supply of Class A drugs. Accordingly, the presumption should be against using this power of arrest for adults found in possession of cannabis. There will be exceptions to this general rule, notably young people. The exceptions are outlined at Paragraph 4 (4.1-4.10) headed “Beyond Simple Possession of Cannabis”. This policy is not intended to interfere with an individual officer’s discretion but to ensure that maximum effort is directed at combating those drugs that cause most harm; specifically cocaine, crack cocaine and heroin. 
2.1 When as a result of any police activity, that is stop and search, vehicle check, search warrant, arrest for other offences, post arrest search in the custody suite, and so on, any adult person is found to be in possession of cannabis the officer will investigate the circumstances seeking admissible evidence of the offence. 
This should include an interview that is sufficient to prove the offence, or identify a defence. This could be as little as two questions such as ‘What is this?’ and ‘Whose is it? If the officer eliminates suspicion of possession with intent to supply, an arrest should not usually take place.”
17.	There then follow procedures for handling cannabis when seized, for notifying the offence, for identifying what is meant by personal use and then under the heading “Beyond Simple Possession of Cannabis”, circumstances where the Notice asserts it is appropriate to arrest for possession of cannabis. It reads:-
“4.1 There will be circumstances where it is appropriate to arrest for possession of cannabis. This is very much left to the discretion of officers who will be expected to take into account the prevailing circumstances in deciding whether to arrest or not. An officer may consider arrest in the following situations.

4.2 Open or repeated use
Context
The smoking of cannabis in public view is not in the spirit of re-classification, as possession of cannabis remains a criminal offence. Equally, where on a local basis, a police officer is aware of a person who is repeatedly found in possession of cannabis, this should be treated seriously and ‘pointing out the offence’ (paragraph 2.5) may not be appropriate.
4.3 A police officer may arrest:
•	Where a person is smoking cannabis in public view.
•	Where locally a person is known to be repeatedly dealt with for possession of cannabis.
4.4	Locally identified Policing problem
Context
There may be circumstances such as a fear of public disorder associated with the use of cannabis, which are causing a local policing problem that cannot be effectively dealt with by other powers.
4.5	A police officer may arrest:
•	A person in possession of cannabis under circumstances that are causing a locally identified policing problem.”
The Notice continues:-
“5. Disposal following arrest
5.1 The decision to arrest must be justified in all cases.  The seizure procedure does not affect police powers or case disposal decision for any other offence(s) that are disclosed in relation to that person.
5.2 Adults arrested for possession of cannabis will be subject to existing case disposal policy, this is No Further Action, Caution or Charge as appropriate. An accused screen will be created in the CRIS and the Proceedings Type completed.”
The Notice concludes:-
“8.1 The policy is intended to reduce the amount of time devoted to policing the possession of a drug, which although harmful to an individual’s health, it not considered to cause damage to society on the scale of crack cocaine, cocaine or heroin. This procedure will allow the effective policing of possession of cannabis, ensuring a proportionate response to the offender and safeguarding the integrity of police officers. The arrest provisions for young people and other aggravating factors will help to protect young people and reduce the potential for anti-social behaviour or disorder.”

19.	As the Notice says, it complemented, in relation to the Metropolitan Police, national guidance issued by the Association of Chief Police Officers (ACPO) in September 2003. That document is headed “Cannabis Enforcement Guidance” and, as its title suggests, its stated purpose was to issue guidance to officers dealing with simple offences of cannabis by adult offenders once the drug was re-classified from Class B to Class C. It points out that, once cannabis was re-classified, it would not have remained an arrestable offence under Section 24 of PACE. It continues:-
“2.1 However the law is being amended in Parliament so that it will continue to be defined as an arrestable offence, but the presumption should be against using this power for simple possession offences.
2.2	There will be circumstances where it is appropriate to arrest for possession of cannabis. This is very much left to the discretion of officers who will be expected to take into account the prevailing circumstances in deciding whether to arrest or not. An officer may consider arrest in the following situations:”

20.	The guidance then identifies circumstances similar to those referred to under the heading “Beyond Simple Possession of Cannabis” in the Notice 3/2004. It should be noted that in relation to the guidance there were set out a number of questions and answers amongst which was:-
“What if an officer makes an arrest outside the guidelines? Will they be open to criticism or legal proceedings? 
Answer
The power of arrest could be used on every occasion, provided that proper grounds for the arrest exist. Therefore, ordinarily, an officer would not be open to proceedings for unlawful arrest. The issue of “criticism” is a matter for individual service policy and management.”
21.	A Home Office Circular 05/2005 referred to the ACPO Guidelines as being directed to ensure that:
•	“Those who flagrantly disregard the law (e.g. smoking cannabis in a public place),
•	Those known locally to be repeatedly dealt with for possession of cannabis (repeat offending),
•	Those whose use of cannabis causes or threatens to cause public order problem, and
•	Those in possession of cannabis in or near premises where young people are present and vulnerable…
are dealt with appropriately – e.g. arrested, followed by a caution or prosecution. It is expected though that, for most offences of cannabis possession, a police warning and confiscation of the drug will be sufficient.”
22.	Notice 3/2004 makes no specific reference to any policy relating to the administration of cautions.
Cautioning

23.	The system of cautioning has no statutory basis. According to Watkins LJ, it derived from a means of dealing with mainly juvenile offenders but only acquired a measure of formal recognition in about 1968 (R-v-Chief Constable of the Kent Constabulary ex parte L [1993] 1 All ER 756 at 763 B-D). The current relevant guidance is contained in Home Office Circular 18/1994. The  purposes are stated to be:-
“- 	to discourage the use of cautions in inappropriate cases, for example for offences which are triable on indictment only; 
-	to seek greater consistency between police force areas;
-	to seek greater consistency between police force areas;
and
-	to promote the better according of cautions.”

24.	Paragraph 8 refers to the offender’s record and comments that multiple cautioning brings this disposal into disrepute. It says:-
“It is only in the following circumstances that more than one caution should be considered; 
-	where the subsequent offence is trivial;
or 
-	where there has been a sufficient lapse of time since the first caution to suggest that it had some effect.”
25.	Paragraph 9 of the Circular refers to significant variations in the use of cautions between the police forces. 
26.	The Circular then sets out national standards commenting that a formal caution is a serious matter. It continues:-
“In order to safeguard the offender’s interests the following conditions must be met before a caution can be administered – 
-	There must be evidence of the offender’s guilt sufficient to give a realistic prospect of conviction;
-	The offender must admit the offence;
-	The offender…must understand the significance of a caution and give informed consent to being cautioned.
Note 2D…. in practice consent to the caution should not be sought until it has been decided that cautioning is the correct course. The significance of the caution must be explained: that is, that a record of the caution, that the fact of a previous caution may influence the decision whether or not to prosecute if the person should offend again, and that it may be cited if the person should subsequently be found guilty of an offence by a court.”
27.	Under the heading “Public Interest Considerations”, Paragraph 3 reads:-
“If the first two of the above requirements are met (evidence of guilt and admission of the offence), consideration should be given to whether a caution is in the public interest. The police should take into account the public interest principles described in the code of Crown Prosecutors. The note to paragraph 3 refers to a presumption in favour of not prosecuting certain categories of offenders, the attitude of the offender to the offence and any regret and need to distinguish between the offenders in relation to group offences.”
The aims of a caution, as identified in the National Standards include:-
“to divert them (less serious offenders) from unnecessary appearance in the criminal courts”.
Legal Principles
28.	The basis of the claimant’s challenge is that the decision to caution is reviewable according to well established public law principles. He derives that proposition from the speech of Lord Diplock in Holgate-Mohammed –v- Duke [1984] 1 AC 437. The plaintiff was seeking damages for wrongful arrest. There was no doubt that the arresting officer suspected the plaintiff of burglary. Lord Diplock stated that the only way in which the lawfulness of the exercise of the executive discretion expressly conferred by statute to make an arrest could be questioned was in accordance with the principles of Wednesbury (see page 443 B). He did not find it necessary to identify those principles but referred to the principle that the discretion must be exercised in good faith (page 443D). The principle in issue in that case was whether the arresting officer had considered an irrelevant factor, namely that there was a greater likelihood that the plaintiff would give true answers if she was questioned under arrest at a police station, (page 444H). The House of Lords concluded that, that was not an irrelevant matter and the officer had exercised his discretion lawfully.
29.	On the foundation that a decision to arrest may be challenged on Wednesbury principles, Mr Starmer QC, on behalf of the claimant, builds the proposition that Notice 03/2004 establishes a policy in relation to both arrest and caution for simple possession of cannabis from which, in accordance with well established public law principles, police officers cannot depart without justification. No such justification has been proffered in the instant case, so he contended. 
30.	Four cases are sufficient to illustrate the interplay between public law and decisions in relation to prosecution and caution. In R-v- Commissioner of Police of the Metropolis ex parte Blackburn [1968] QB 118 Lord Denning MR responded to Mr Blackburn’s attempt to compel the Commissioner of Police to prosecute illegal gaming. The Commissioner, said Lord Denning:-
“In all these things…is not the servant of anyone, save for the law itself. No minister of the Crown can tell him that he must, or must not, keep observation on this place or that; or that he must or must not, prosecute this man or that one. Nor can any police authority tell him so. Responsibility for law enforcement lies on him. He is answerable to the law and the law alone….” (136 b-c)
31.	Lord Denning continued by referring to the discretion of Chief Officers of Police as to how to deploy their forces:-
“It is for the Commissioner of Police of the Metropolis or the Chief Constable, as the case may be, to decide in any particular case whether enquiries should be pursued, or whether an arrest should be made, or prosecution brought. It must be for him to decide on the disposition of his force on the concentration of his resources on any particular crime or area. No court can or should give him direction on such a matter. He can also make policy decisions and give effect to them, as, for instance, was often done when prosecutions were not brought for attempted suicide. But there are some policy decisions with which, I think, the courts in a case can, if necessary, interfere. Suppose a Chief Constable were to issue a directive to his men that no person should be prosecuted for stealing any goods less than £100 in value. I should have thought that the court could countermand it. He would be failing in his duty to enforce the law.” (136 e-f). 
32.	Mr Blackburn lost but only because the police had revoked the policy decision not to prosecute.
33.	The courts may appear, these days, to be more interventionist, even in relation to decisions relating to prosecution. There are cases where, particularly in relation to juveniles, the courts have required departures from policy in relation to criminal proceedings to be justified. But the courts have done so with reluctance, ever mindful of the need not to interfere with operational decisions by those best placed to meet the demands of the practical application of the criminal law. In R-v- Chief Constable of the Kent County Constabulary ex parte L (a minor) [1993] 1 ALL ER 756 two juveniles challenged a decision to prosecute. L contended that the decision to prosecute and not to caution breached the code for Crown Prosecutors issued pursuant to Section 10 (1) of the Prosecution of Offences Act 1985 and guidelines issued by the Home Secretary. B could not be cautioned because she had not admitted the offence but sought to quash a decision to prosecute. Watkins LJ concluded:-
“In respect of juveniles, the discretion of the CPS to continue or discontinue criminal proceedings is reviewable by this court but only where it can be demonstrated that the decision was made regardless of or clearly contrary to a settled policy at the Director of Public Prosecutions evolved in the public interest, for example the policy of cautioning juveniles, a policy which the CPS are bound to apply where appropriate to the exercise of their discretion to continue or discontinue criminal proceedings. But I envisage that it would be only rarely that a defendant could succeed in showing that a decision was fatally flawed in such a manner as that.”
34.	Both applications were dismissed. But the minatory words of Watkins LJ are of importance. Even in the case of juveniles he found it:-
“very difficult to envisage, with regard to that policy (the requirement that a prosecution is required in the public interest) the circumstance, fraud or dishonesty apart possibly, which would allow the challenge to a decision to prosecute or to continue proceedings unless it could be demonstrated, in the case of a juvenile, that there had been either a total disregard of the policy or contrary to it, a lack of enquiry into the circumstances and background of that person…” (770 h-j).
35.	He continued by contrasting the position of juveniles with those of adults in whose case he thought that judicial review of a decision not to discontinue a prosecution was unlikely to be available.
“The danger of opening too wide the door of review of the discretion to continue a prosecution is manifest and such review, if it exists, must, therefore be, confined to very narrow limits.” (page 771 a)
36.	It is to be noted that in that case Watkins LJ regarded the decision of the senior police officer to prosecute as stern and accepted that some other police officer might have taken the opposite view. But that did not lead to the conclusion that there was no proper exercise of discretion ( see 771d). 
37.	It must be stressed, that in that case there was a clear and settled policy of the prosecuting authority (DPP), issued pursuant to statute.
38.	A plain departure from clear guidelines as to the conditions which must be satisfied before a caution could be administered was demonstrated in two cases.  In both those cases the court was concerned not with the decision whether to administer the caution or not, but whether, once a decision to caution had been made, the conditions for administering a caution, clearly identified in settled guidelines, had been fulfilled.
39.	In R –v- Commissioner of Police of the Metropolis ex parte P [1995] 160 JP 367 a twelve year old juvenile had been misled by inaccurate advice as to what was necessary to establish his guilt of an offence of shop lifting. Moreover, in interview he had made neither a clear nor a reliable admission of guilt. The Divisional Court quashed the caution. Home Office Circular 18/1994 required evidence of an offenders guilt, admission of the offence and informed consent. The court identified breaches of those requirements. Simon Brown LJ said:-
“This court can properly intervene if a caution is administered in clear breach of the guidelines set out in the Home Office circular.”
40.	But he accompanied that conclusion with words which limited the implication of the decision:-
“I do not say that the court invariably would intervene in such circumstances. That must always be a matter for its undoubted discretion. But a clear breach would, in my judgement, bring the case properly within the purview of the court’s supervisory jurisdiction.” (p 371 e)
and he concluded:-
“Nothing contained in my judgement is intended to offer any sort of general encouragement to those cautioned to challenge the legality of their cautions.  …in broad terms police officers responsible for applying this circular must enjoy a wide margin of appreciation to the nature of the case and whether the preconditions for a caution are satisfied.” (p 375 e)
41.	Similarly in R –v- Commissioner of Police of the Metropolis ex parte Thompson [1997] 1 WLR 1521 the court upheld the challenge to a caution where there had been an improper inducement to admit the offence. Schiemann LJ re-emphasised Simon Brown LJ’s confined approach to challenge of the administration of a caution. Again, this was not a challenge to the decision to caution but rather to the propriety of administering a caution where the conditions for administration had not been fulfilled, once a decision to caution had been made. These cases afford no support to the proposition that courts will interfere with a decision to caution provided that the pre-conditions to caution are satisfied.
42.	Walker J discovered a decision of the Court of Appeal Criminal Division in R –v- Addaway [2004] EWCA Crim 2831 in which the decision of a local authority to prosecute for a false trade description was successfully challenged. That was a highly unusual case. The local authority had a clear and settled policy not to prosecute save in cases of fraud or deliberate breaches of the Act. The Court of Appeal upheld an appeal against the refusal of the judge to stay the prosecution in circumstances where there was no evidence of fraud or a deliberate breach and it was apparent that the prosecution was oppressive. No proper consideration had been given by the local authority to its own trading standards prosecution policy and, indeed, the prosecution had sought without any justification to cross-examine so as to demonstrate fraud.
43.	These authorities establish:-
i)	Generally, the reluctance of the courts to intervene in relation to decisions to prosecute, even in the case of juveniles;
ii)	The reluctance of the courts to intervene in relation to the administration of cautions;
iii)	A refusal to intervene save where the policy which it is suggested has been breached is clear and settled; and
iv)	The breach is itself established.

44.	It is unsurprising that the courts have been so reluctant to intervene in relation to decisions taken concerning prosecutions and particularly in relation to operational decisions of the police. In relation to the decision of a police officer to make an arrest, there is one feature it is vital to bear in mind to which I have not yet drawn attention. That relates to the original jurisdiction of a constable to keep the Queen’s Peace. That derives from the office of constable and the oath which each constable swears on appointment. It finds manifestation in what, until it was substantially amended on 1st January 2006 by Section 110 of the Serious Organised Crime and Police Act 2005, was Section 24 of the Police and Criminal Evidence Act 1984. Section 24 of PACE provided:-
“i) the powers of summary arrest conferred by the following subsection shall apply:
c) …to the offences listed in Schedule 1A and in this Act “arrestable offence” means any such offence.
…(6) Where a constable has reasonable grounds for suspecting that an arrestable offence has been committed, he may arrest without a warrant anyone whom he has reasonable grounds for suspecting to be guilty of the offence.”
45.	Any suggestion that a policy may limit the power to arrest must have regard to the statutory power conferred on each and every police constable.
Conclusion
46.	The claimant starts with a profound difficulty.  If he is right, then by the promulgation of Notice 3/2004, the Metropolitan Police Commissioner has rendered it unlawful for a police officer, presumably within the relevant metropolitan area, to arrest or caution anyone for simple possession of cannabis, absent the presence of one of the circumstances identified in the Standard Operating Procedures(“SOP”).  This is a startling proposition particularly when Parliament expressly conferred a power of summary arrest on police constables at the very moment it re-classified cannabis. Any suggestion that arrest or caution is unlawful must be viewed in the context of both the general power of arrest conferred by S.24 of PACE and the explicit power conferred in relation to possession of cannabis conferred by the amendment in Section 3 of the 2003 Act.
47.	Of course, any acknowledgement that a court may intervene to prevent a prosecution in some circumstance must carry with it an acceptance that the court may prevent prosecution for a crime of which a claimant may be guilty.  Such an acceptance is implicit in any case where the court is prepared to consider the failure of a prosecuting authority to follow guidelines.  But we are here dealing with the operational activities of the police.  It might be thought risible to suggest that a police inspector, at 4.a.m, failed properly to analyse the interstices and relationship between the Notice 3/2004 and Home Office Circular 18/1994, before deciding to caution, and so acted unlawfully, were not the implications of the arguments so serious.  But if the claimant is right, the inspector was acting unlawfully.  Even before one reaches the point of analysing the policy on which the claimant relies, it is difficult to see how the  dissemination of a notice could remove the legality of the exercise of the very power which Parliament had conferred on the same day.
48.	This constitutes a fundamental reason why Mr Starmer QC’s arguments cannot be accepted. He accepted that it was a necessary consequence of his submission that the arrest policy made the administration of the caution unlawful, that any prosecution of Mr Mondelly would have been unlawful as well. This he accepted would apply to any individual who was found in simple possession of cannabis where there were no aggravating circumstances as described in the SOP. Even if he were not arrested, he could not be prosecuted by the issuing of a summons. So the policy on arrest when read across to cautions, as Mr Starmer QC contended it should be, becomes a prohibition on prosecution. That is an utterly misconceived approach to the meaning and effect of the policy. It demonstrates powerfully why his approach to the arrest policy takes it several steps beyond its stated confines and purpose. There is nothing in it at all to suggest that the authors thought they were creating such a policy, let alone one which required the application of hindsight as Mr Starmer QC urged.  
49.	 Were there to be a police/CPS policy that no one should be prosecuted for simple possession of cannabis unless it fell within the aggravating circumstances specified, and if that were said to make a decision to prosecute unlawful in such circumstances, it would be an unlawful policy itself. Parliament did not enact those aggravating factors into the offence of simple possession, and it is not for executive prosecution policy to change it. The implication of Mr Starmer QC’s argument is that by policy, a police force or the Home Office, could suspend or dispense with part of the law as enacted by Parliament. The statutory power of arrest and the power to prosecute would become a mere power of seizure except if non-statutory and variable aggravating features were present. This would be akin to a policy not to prosecute for theft, and merely to retrieve stolen goods, unless their value exceeded £100, not far distant from the example of an unlawful policy given by Denning MR in R v Commissioner of Police of the Metropolis ex parte Blackburn [1968] QB 118, at 136.
50.	But when it comes to analysis of the Notice on which the claimant relies, the argument becomes even more difficult.  Even if one could contemplate a policy having the effect for which the claimant contends, in order to succeed he must establish a clear policy not to administer a caution for simple possession of cannabis, departure from which must be justified.

51.	The claimant must therefore establish such a clear policy by reference to the policy relating to arrest and prosecution for simple possession of cannabis, which, in some way limits the policy relating to cautioning. In my judgment, he cannot do so.
52.	Firstly, there is no clear policy precluding arrest, caution or prosecution for simple possession of cannabis on which anyone found in possession of cannabis can rely. Notice 3/2004 on which the claimant relied expressly provides that it is not intended to interfere with the discretion of a police officer. If it was intended to circumscribe an officer’s statutory discretion to arrest then it is seriously misleading. The policy specifically states under Paragraph 1 of the SOP that it is not intended to interfere with an individual officer’s discretion (see Paragraph 1.2); that echoes the ACPO Guidance particularly the question and answer I have already identified. Even the description of circumstances where it is appropriate to arrest emphasises again that it “ is very much left to the discretion of officers who will be expected to take into account the prevailing circumstances when deciding to arrest or not”.
53.	Secondly, there is nothing in the arrest policy which states that it is applicable to cautioning or prosecution after arrest. A policy on arrest, based on its own rationale and hedged about with the maintenance of a constable’s discretion as it is, cannot sensibly be interpreted as a policy which prohibits cautions or prosecution. On the face of it, only the claimant has done something unlawful. He was lawfully arrested, and later lawfully cautioned for committing, as he admits, a minor criminal offence. Yet, submits Mr Starmer QC, the Inspector acted unlawfully in cautioning the claimant who had committed an offence; the Inspector was legally obliged to take no further action in respect of the offence.  The application to the caution of the policy on arrest is misconceived. There is a policy in place which deals with cautions, which does not adopt the arrest policy or limit the application of the caution in some related way. The public interest in administering a caution was considered in line with the relevant policy. There is nothing in the caution policy which suggests that the public interest in cautions should be affected by a different policy on arrests.

54.	Thirdly, whilst it is true that the Notice does refer to clear guidance and accountability, its purpose relates to deployment of police forces:-
“ensuring that the least amount of policing time possible is spent dealing with a drug of lesser classification… to provide direction and focus towards governmental and policing priorities”.
It is, thus, aimed at ensuring that police time and effort is spent upon more serious offences. It is difficult to contemplate that one who chooses to break the law by possessing cannabis could rely, to avoid caution or prosecution, upon a policy designed to ensure efficient policing and the avoidance of confrontation by arrests in sensitive areas. 
55.	Fourthly, the policy is itself unclear. Whilst the policy statement refers to no further action being taken, which could give rise to a possible inference that there should be no caution (see policy statement and SOP 5.2) it does not say so explicitly. In particular there is nothing whatever in the Home Office guidance relating to cautions which cross refers to the Police Notice relating to possession of cannabis. It is hardly a mark of a clear and settled policy when the policy relating to caution is not amended to take account of the policy relating to possession of cannabis.
56.	I conclude that there is no clear and settled policy not to arrest or prosecute for simple possession of cannabis. The absence of any such clear and settled policy is fatal to the claimant’s case. 
57.	In any event, there was no breach of the SOP. Mr Starmer relied on a short passage, which says that where a person has been arrested for another offence which is not being pursued but in the course of which the simple possession of cannabis is discovered, arrest for simple possession should not usually follow. Mr Mondelly was not re-arrested for simple possession and there was no non-compliance with that SOP. The SOP says that if arrest is not appropriate, the simple possession offence should be recorded but that was not a criminal record. The SOP does not deal with whether or not there should be any further prosecution or caution in express terms, although it would appear to be the expectation that that would be the end of the matter.
58.	The highest the claimant could pitch his case, in reliance on general public law principles, is that in considering whether to caution or not, a police officer ought to bear in mind that most of those found in possession of cannabis, particularly in their own homes, are unlikely to be arrested. In the light of ACPO guidance and Police Notice 3/2004 it is likely that arrest for such an offence will be rare save in circumstances identified in Paragraph 4 of the SOP. It is also likely that absent arrest or an arrest for some other offence no further action will be taken. Accordingly, so Mr Starmer QC argues, the inspector failed to take into account a relevant consideration, namely the usual escape of a cannabis smoker from the consequences of his unlawful activity. 
59.	But there is, in my view, no requirement on a police officer to bear those considerations in mind when considering whether to caution for an offence.  Consistency is, doubtless, an admirable goal but the width of judgement open to each officer is such as to produce an absence of uniformity.
60.	It is important to bear in mind the wide scope for judgement a police  officer may exercise when  considering whether to caution or not. As Watkins LJ pointed out, in ex parte L,(at 771d), the mere fact that one inspector takes a harsh view and another does not, does not begin to justify an assertion of Wednesbury unreasonableness. No one who breaks the law can be heard to complain because some have been prosecuted and others have not. Police forces across the country should aim for consistency but so various are the different factual considerations, so wide the margin for judgement a public law challenge on the grounds of inconsistency is not to be contemplated.  True it is there is no express policy preserving the right to prosecute in some cases but not in others, as in R –v- Inland Revenue Commissioners ex parte Mead. (65 TC 1 & [1993] 1 All ER 772). None is needed. The possibility of caution or prosecution is a powerful deterrent.  It is absurd to think that anyone should be permitted to smoke cannabis, confident that he will neither be cautioned nor prosecuted unless an aggravating feature is present, all the more so to imagine that he can invoke the jurisdiction of this court because he knows that in other cases, no action was taken. It cannot be suggested that someone found in possession of cannabis in Notting Hill could have complained of his arrest and prosecution, because someone escaped such consequences in Lambeth, where the policy in question originated.
61.	Inspector Barrett did not disregard Notice 3/2004. His account of that policy is too brief accurately to summarise what it says. But he is correct as to its essential thrust; it creates no policy preventing an arrest still less a caution in respect of possession of cannabis. 
62.	In relation to his consideration of a caution the mere assertion of the two features that:-
“It was inappropriate to “no further action” this matter”
and that Mr Mondelly had admitted possession in interview, may not be sufficient to demonstrate consideration of the public interest in cautioning. But the reference to a previous caution was a factor on which he was entitled to rely. Further, as the inspector says, if Mr Mondelly had refused to accept a caution it would have been a matter for the CPS to decide whether to prosecute or not. In my view provided they had properly considered the evidential and public interest requirements, a prosecution would have been permissible. Of course, Mr Mondelly was unlucky. But we reject the application which seeks to absolve from the administration of a caution one who has chosen to break what is still the law.
63.	I should add that Ouseley J has contributed to this judgement. I would dismiss this application.
Ouseley J:	
64.	I agree.
Walker J:
65.	I acknowledge the strong force of the reasoning which has led Moses LJ and Ouseley J to conclude that this application should be dismissed. When I began to read the papers in this case my instinctive reaction was that the court should not interfere with police discretion in the administration of cautions. However when I completed reading the papers there seemed to me to be very strong arguments the other way. Powerful oral submissions were made at the hearing by Mr Keir Starmer QC and Mr Hugh Southey for the claimant (“Mr Mondelly”) and by Mr Jason Beer for the defendant (“the Commissioner”). After taking time to reflect on all the arguments, my conclusion is that, for my part, I would have allowed this application for judicial review. 
66.	To my mind the caution administered to Mr Mondelly clearly contravened the Commissioner’s policy on policing simple possession of cannabis, and for no good reason. The injustice to Mr Mondelly is such that the court should intervene.
67.	Further, it is an acknowledged fact that those who arrested Mr Mondelly were mistaken in thinking that he was guilty of anything other than simple possession of cannabis in his flat. The Commissioner had adopted a policy which plainly would not have led to Mr Mondelly’s arrest, let alone a criminal record, were it not for this mistake. In my view it is unjust that Mr Mondelly should have received a caution, and the accompanying criminal record, when if the arresting officers had not been mistaken they would have applied the policy with the result that there would have been no arrest, no caution, and no accompanying criminal record. Moreover, if Mr Mondelly had been prosecuted rather than cautioned then he would have been able to seek a remedy against injustice by seeking a stay of the proceedings as an abuse of process. In the absence of any rational reason for not applying the policy, there would have been strong grounds to urge the grant of a stay. In my view it is unjust that Mr Mondelly should have received a caution, and the accompanying criminal record, when if his case had gone to trial in the criminal court there would have been strong grounds to stop it for abuse of process. I take account of warnings in earlier cases to the effect that only in exceptional cases should the court intervene in relation to the cautioning of offenders. In each of these two respects the injustice seems to me such as to render this case exceptional. 
68.	I do not say that Mr Mondelly should have escaped free of any sanction. Application of the policy would have led to confiscation of his cannabis and a warning to him to mend his ways. What I view as unjust is the taking of taking of steps beyond confiscation and a warning on this occasion, once the mistake was appreciated. The just course was to act in accordance with the policy by confiscating the cannabis and giving a warning. That would have had the consequence – of which Mr Mondelly could not in my view complain – that if he did not mend his ways and became known locally as a repeat offender then in accordance with the policy he could be arrested, followed by a caution or prosecution.
69.	In setting out my reasons I start by explaining in general terms why I concluded that my initial reaction – which I suspect may be shared by many others - was unsound. I then describe some features of the downgrading of cannabis from class B to class C, before turning to my analysis of the arguments.
The initial reaction not to interfere
70.	It may be thought to be a principle of the criminal justice system that those who have committed criminal offences should be apprehended, convicted either on a plea of guilty or after trial, and sentenced for their crimes. I shall call this “the ordinary enforcement principle.” In Mr Mondelly’s case he has committed the criminal offence of possession of cannabis. Far from applying the full rigour of the ordinary enforcement principle, the Commissioner through Inspector Barrett has let him off with a caution. My instinctive reaction was to ask the rhetorical question, how can Mr Mondelly possibly complain of what appears to be an act of mercy on the part of the Commissioner?
71.	The first factor which leads me to think that this initial reaction is unsound concerns the ordinary enforcement principle itself. It is not absolute. As Lord Denning observed in the Blackburn case, the Commissioner can make policy decisions and give effect to them, as, for instance, was often done when prosecutions were not brought for attempted suicide. 
72.	Second, at a strategic level, such policies are susceptible to judicial review – as in the example given by Lord Denning of a policy not to prosecute for theft of goods less than £100 in value. 
73.	Third, at an operational level, a decision to prosecute which with no rational reason departs from a relevant enforcement agency’s policy, or is otherwise arguably oppressive, brings into play the criminal court’s power to stay the prosecution for abuse of process. 
74.	Fourth, there may be a separate question whether any arrest involved was “unlawful” in the sense that the person arrested can bring an action for damages. The primary questions in such an action will usually be whether the claimant was imprisoned or was subject to the use of force by the defendant, and if so whether the defendant had legal justification. There may sometimes be an overlap with questions arising on an application in the criminal courts or on judicial review, but the focus will differ.
75.	Fifth, a caution is of course a less severe manner of proceeding than a criminal prosecution. However it has at least four potentially serious consequences for Mr Mondelly. The fact of a previous caution may influence the decision whether or not to prosecute if in future the police think he has done something criminal. Next, if in a later prosecution he claims to be innocent, the caution may place him at a disadvantage. In an appropriate case the prosecution can apply to rely on the previous caution to support their case that he is guilty of the new alleged offence. Even if they do not do this, the court may in an appropriate case refuse to allow him to present himself as a person of good character in support of his case that he is innocent of the new alleged offence. The third consequence is that the caution may be cited if on a later occasion he is convicted of an offence by a court – in which event it may be an aggravating factor when the court determines the sentence on that later occasion. Finally in this regard, anyone learning of the caution, and knowing of the policy, would assume that Mr Mondelly must have been guilty not just of simple possession of cannabis but of possession with at least one of the aggravating features identified in the policy.
76.	Sixth, while the public law court will often need to be particularly cautious before intervening in an operational decision, I am reluctant to hold that it can never do so. In particular, if the police act contrary to a clear policy as to law enforcement in relation to specific offences, it may well be that those complaining of injustice would be offenders. That fact alone should not in my view lead the courts to declare departure by the police from policy to be a complete “no go” area. 
77.	Seventh, an important question of principle arises if a caution is administered in circumstances where it is known that but for a mistake by arresting officers no action beyond confiscation and a warning would have been taken against the offender. Even if the caution is not contrary to express policy, concern in any event arises from the fact that if it were not for the mistake then the policy would have come into play. 
78.	Eighth, an important question of principle arises if a caution is administered in circumstances where the court would have had strong grounds to stay a prosecution. In those circumstances there is a strong risk of injustice to the citizen. Had the ordinary course of prosecuting (rather than cautioning) been taken, there would have been strong grounds for the court to intervene to ensure that the citizen would have no criminal record whatever. It is difficult to see why, merely because the police decided to caution rather than to prosecute, the citizen should have any less protection from the courts.
The downgrading of cannabis from class B to class C
79.	With effect from 29 January 2004 cannabis was reclassified from a Class B to a Class C drug under the Misuse of Drugs Act 1971. Anticipating this, the Association of Chief Police Officers of England, Wales and Northern Ireland (“ACPO”) issued “Cannabis Enforcement Guidance” dated 12 September 2003 (“the ACPO Guidance”). This indicated that, while possession of cannabis would continue to be an arrestable offence, the presumption should be against using the power of arrest for simple possession offences. This was adopted by the defendant (“the Commissioner”) in a Police Notice 3/2004 (“the Police Notice”), which complemented the ACPO Guidance and was addressed, among others, to operational officers of the Metropolitan Police Service who had specific responsibilities in the investigation of offences of cannabis possession. Passages from the Police Notice are set out in the judgment of Moses LJ. A feature of the notice which I think relevant is that it was headed “Policing Possession of Cannabis as a Class C Drug”. Similarly the heading for Paragraph 4 of the Standard Operating Procedures was in general terms: “Beyond simple possession of cannabis.” 
80.	The re-classification of cannabis from Class B to Class C was brought about by the Misuse of Drugs Act 1971 (Modification) (No. 2) Order 2003. The order was made on 10 December 2003 and came into force on 29 January 2004. It had been approved by each House of Parliament. As explained in Home Office Circular 05/2004, distributed on 16 January 2004, other changes took effect in conjunction with the re-classification. First, s 3 of the Criminal Justice Act 2003 (“the 2003 Act”) amended the Police and Criminal Evidence Act 1984 so that possession of cannabis or cannabis resins remained an arrestable offence despite the re-classification. Second, schedule 28 and s 284 of the 2003 Act increased the penalties for drug-related offences, in particular that for trafficking Class C drugs which was increased from 5 years to 14 years imprisonment. Annex B to the Circular set out background information relating to the re-classification of cannabis. This included the following:
“2. In October 2001, the Home Secretary announced that he was asking the Advisory Council on the Misuse of Drugs for advice on the classification of cannabis. In March 2002, the Council published a report in which it recommended that cannabis – and all cannabis related substances – should be reclassified as Class C drugs. …
3. The Council said that although cannabis is unquestionably harmful, its classification as a Class B drug was disproportionate in relation both to its inherent toxicity (harm), and to that of other substances, such as the amphetamines, which are Class B drugs. In July 2002, the Home Secretary announced in Parliament that he accepted the advice of the Council, and accordingly he would bring proposals to reclassify cannabis to Class C.
4. The main reasons for the Government’s decision to take steps to reclassify cannabis as a Class C drug were:
(i)		that an accurate reflection of the assessment of the relative harmfulness of drugs, in line with the scientific and medical advice it had received from the Advisory Council on the Misuse of Drugs, would give the misuse of drugs legislation greater credibility and enable a more convincing and ultimately more effective messages to be conveyed to young people about the dangers of misusing different types of drug; and
(ii)		that reclassification would send a clear message that the Government’s priority is to tackle Class A drugs, such as heroin, cocaine and crack cocaine, as they cause the most harm to users, their families and the wider community.
5. Reclassification means that the maximum sentence for the possession of cannabis will be reduced from five to two years’ imprisonment. However, under the cannabis enforcement guidance issued by the Association of Chief Police Officers (ACPO) to police forces in September 2003, there is a presumption against arrest for adults (i.e. those aged under 18 or over) who are found in possession of cannabis. The guidance, backed by the power of arrest under section 3 of the Criminal Justice Act 2003, is directed at ensuring that:-
•	those who flagrantly disregard the law (e.g. smoking cannabis in public place), 
•	those known locally to be repeatedly dealt with for possession of cannabis (repeat offending)
•	those whose use of cannabis causes or threatens to cause a public order problem, and
•	those in possession of cannabis in or near premises where young people are present and vulnerable (e.g. schools, youth clubs and play areas), 
are dealt with appropriately – e.g. arrested, followed by a caution or prosecution.”

Analysis of arguments in the present case
81.	Mr Starmer on behalf of Mr Mondelly advanced three arguments. The first had two elements. These were (1) that the caution involved a refusal to apply the policy in the Police Notice, and (2) that the discretion of the police to administer a caution was limited because, in the absence of a good reason for doing so, it was unlawful to refuse to apply the policy to Mr Mondelly. 
82.	The second argument was that the cautioning of Mr Mondelly was inconsistent with the primary purpose underpinning the administration of cautions – namely, to divert offenders from unnecessary appearance in the criminal courts.
83.	 The third argument was that it was unreasonable in the Wednesbury sense to caution for simple possession where the circumstances known at the time of caution would not warrant arrest.
84.	Against these arguments Mr Beer on behalf of the Commissioner advanced six propositions:
(1)	A constable exercises an original jurisdiction. His powers of arrest are statutory, and not found in guidance documents. Mere departure from guidance did not render an arrest unlawful.
(2)	Cautions are regulated by Home Office Circular 18/1994. Nothing in this case was inconsistent with that circular. 
(3)	The Police Notice contained no express prohibition on cautioning, or arresting, for cannabis possession even if that would be inconsistent with the policy set out in that notice.
(4)	The policy in the Police Notice did not address whether a person may be cautioned for simple possession of cannabis where they have been arrested for some other offence.
(5)	In any event Mr Mondelly could not claim the benefit of the policy, as in his case the aggravating feature of “open or repeated use” was present.
(6)	Throughout his submissions, Mr Beer stressed that the circumstances in which judicial review of a decision to caution was appropriate were “severely circumscribed”. 
85.	In the analysis below I shall work by reference to Mr Starmer’s three arguments, dealing with Mr Beer’s propositions as they arise in relation to those arguments.
First element of the first argument: what did the policy in the Police Notice cover? 
86.	The main issue argued in this regard was whether the relevant policy was concerned only with the question when an arrest should be made, with the result that the policy did not apply to the cautioning of those who had been arrested for another offence. Mr Starmer acknowledged that the Police Notice was in part at least concerned with arrest, but asserted that the references to “no further action” were not limited to the context of arrest. The administration of a caution was further action and thus contrary to the policy. 
87.	He found support in the heading to the Police Notice. It was concerned with “policing” – a word apt to cover cautioning as well as arrest. The intention to lay down a policy of a general nature was, he submitted, also apparent from paragraph 2.1, showing that the policy applied when possession of cannabis was detected “by any police activity” – and in particular after arresting for other offences. He submitted that the procedures in paragraphs 3, 4 and 5 were consistent with this approach. Such an approach, he suggested, reflected the aim summarised under the heading “Conclusion” in paragraph 8.1: ensuring a proportionate response to the offender. 
88.	Mr Beer relied on all six of his propositions in answer to Mr Starmer’s first argument. At this stage I shall deal with propositions (4) and (5). I shall turn to propositions (1), (2), (3) and (6) when I come to the second element of the first argument. 
89.	In support of proposition (4) Mr Beer submitted that the Police Notice was all about arrest. Paragraph 2.1 was to be read as meaning, if a suspect has been arrested for something else, and officers conclude the suspect is also guilty of simple unaggravated possession of cannabis, then the policy is not to arrest for cannabis possession. This, he submitted, said nothing about whether the suspect was to be cautioned for cannabis possession. He added that the policy was confined to arrests, and was appropriate to arrests for reasons which could not be read across to cautions. These were (i) to reduce friction and conflict between the police and the public (in particular young people) in public, and (ii) to reduce the amount of time officers are required to spend after making arrests for simple possession. Both points appear to me unpersuasive. As to suggested reason (i) the policy applies whether or not an arrest is in public. Suggested reason (ii) is, if anything, an acknowledgement that the policy applies to what happens after arrest. It is entirely consistent with this for the policy to apply to the decision whether to caution someone who has already been arrested: applying the policy of no further action will reduce the time officers are required to spend after arrest. In this instance there is a clear read-across to cautions. It is difficult to see why, if a stage is reached where the only offence thought to have been committed is simple possession of cannabis, the fact that the arrest was for a different offence should matter.
90.	In this context it is suggested that an offender such as Mr Mondelly can hardly rely on a policy aimed at ensuring that police time and effort is spent upon more serious offenders. It is true that such an aim appears both in Circular 05/2004, the ACPO Guidance, and in the Police Notice under the heading “Purpose.” However, it is to be noted that the Police Notice, when describing this aim, goes on to say: “It will ensure the integrity of offenders and police officers …”. The underlying thought is explained under the heading “Benefit”. The “informal disposal” practices in Lambeth had implications for integrity. In order to allay fears in this regard the policy in the Police Notice provided a framework “… protecting the officer and offender, thereby improving morale and public confidence.” The last sentence under “Benefit” makes clear that this is all in the context of scientific advice that while cannabis is a harmful drug, its classification in class B was disproportionate. As annex B to Circular 05/2004 records, a main reason for reclassification was to give the drugs legislation greater credibility and to enable a more convincing and ultimately more effective message to be conveyed to young people. These motives all point in my view to a major objective of achieving consistency in an enforcement policy which takes account of the government’s reasons for downgrading cannabis. It will not thwart, and may well advance, this objective if an offender who is denied the benefit of the policy is able to complain of real injustice caused by treating his case inconsistently with others.
91.	Proposition (5) was advanced very much as a subsidiary submission. I can deal with it shortly. It is clear from the ACPO Guidance that “open” or “repeat” offending was seen as aggravating because flagrant disregard of the law had the potential to undermine the basic concept that possession of cannabis remained illegal. There was nothing “open” about Mr Mondelly’s possession of cannabis. The offence of possession was committed on his own in the privacy of his flat. Was he a “repeat offender”? The policy envisages a caution or prosecution for someone found with cannabis if that person is “known locally to be repeatedly dealt with for possession of cannabis”. Prior to his arrest Mr Mondelly had not been “repeatedly dealt with for possession of cannabis”, and there was no question of being “known locally” for this. He had a single caution 2 years previously. I have no hesitation in rejecting proposition (5). 
92.	I am conscious that a court should tread warily before rejecting an interpretation of policy put forward by the policy-maker. Even so, proposition (5) strains the language of the policy too far. In my view the same is true of proposition (4). I accept that the policy is in large part set out by reference to the circumstances when an arrest is appropriate. However the Home Office Circular made it clear in paragraph 5 of Annex B that the national aim was to ensure that adults found in possession of cannabis were “dealt with appropriately – e.g. arrested, followed by a caution or prosecution.” Thus an arrest is merely an example of the disposals envisaged as ensuring that offenders are “dealt with appropriately”. To my mind, paragraph 2.1 of the Police Notice makes explicit that the policy sets out what should happen generally when any police activity results in an adult being found in possession of cannabis. This is consistent with the heading “Policing Possession of Cannabis as a Class C Drug” and, in my view, implicit in other paragraphs. I cannot accept that the Police Notice at paragraph 5.2 envisaged that, once somebody had been arrested, case disposal could proceed as if there were no policy. This would be contrary to Mr Beer’s own suggested reason (ii) for the policy. Moreover, it is a complete misreading of paragraph 5.2, which in context is plainly concerned to state that where it is appropriate to make an arrest for simple possession of cannabis, then ordinary procedures for case disposal will follow. 
93.	Within a context of general enforcement, particular passages in paragraphs 3, 4 and 5 of the policy focus on arrest. Working by reference to the circumstances when an arrest is appropriate is a natural approach to take, for arrest is the normal first stage of the enforcement process. If that first stage is not appropriate then in the ordinary course it goes without saying that jumping to later stages would be equally inappropriate. 
94.	Accordingly, I conclude that the first element of the first argument is made good: the cautioning of Mr Mondelly was contrary to the policy.
The second element of the first argument: consequence of contravening the policy.
95.	Mr Starmer acknowledged that mere failure to comply with a policy did not mean that the court should interfere. His argument was that in the absence of a good reason, it was unlawful for a public authority to apply a policy to A and B and not to C. The jurisdiction of the court to intervene where a caution was administered contrary to policy was established by the cases of P  and Thompson. The court had refused to interfere in the revenue cases, but they were cases where the policy expressly said that prosecutions might be random, and it had been possible to identify good reason for that course. By contrast, the policy in the present case was intended to ensure transparency and consistency. It was important that the public should be able to rely on even-handed application of policy. This went beyond the present questions about possession of cannabis. There were police policies on domestic violence and on ethnic minorities. It was important that both victims and offenders knew where they stood. As to concerns about the court second-guessing operational decisions, Mr Starmer pointed to Holgate-Mohamed, where Lord Diplock contemplated with equanimity the application of the Wednesbury criteria when deciding whether an operational decision involved the commission of a tort.
96.	On this point of principle, Mr Beer’s first answer was proposition (1). Relying on well known cases about the discretion of constables, the statutory nature of their powers of arrest, and their independence from the executive, he submitted that failure to follow guidance could not make an otherwise lawful arrest unlawful. In my view this submission was aimed at the wrong target. It is no part of Mr Mondelly’s case (as presently formulated for the purposes of seeking judicial review) to assert that the Commissioner, by issuing the Police Notice, has made it unlawful and tortious to arrest outside the policy. Mr Mondelly was arrested for permitting his premises to be used for the consumption of cannabis. Whether that arrest was lawful or unlawful has, in the circumstances of this case, no bearing on whether Mr Mondelly has good grounds in public law to complain of the decision to caution him for simple possession of cannabis. Indeed, Mr Beer accepted that the cases about cautions – starting with L, and followed by P and Thompson – show that when the police exercise powers of a public nature they may in principle be open to judicial review. In these circumstances proposition (1) does not assist the Commissioner.
97.	It is convenient next to deal with proposition (3). It is true that the Police Notice, the ACPO Guidance, and Home Office Circular 5/2004 do not expressly prohibit acting otherwise than in accordance with the policy. It is right that they should refrain from such a prohibition. As Mr Beer accepted, policy cannot be allowed to fetter discretion. There may be good reason to depart from the policy. It follows that the failure to prohibit departure from policy does not of itself demonstrate that such a departure should be immune from judicial review. Equally, as it seems to me, stress placed in these documents on the retention of police discretion cannot be read as intending to give officers carte blanche. A clear aim that emerges from all the documents is that there should be consistency. Giving officers carte blanche would completely undermine that aim – indeed it would turn the policy into a false promise. Haphazard delivery of the policy would destroy the credibility of the police, which in turn would so fundamentally undermine crucial aims of the policy that it would be better not to bother with the policy at all. 
98.	As to proposition (2), there is an overlap with Mr Starmer’s second argument. I shall discuss in that context the assertion that the caution administered to Mr Mondelly was consistent with the policy of Circular 18/1994 on cautioning. Even if this assertion is right, I do not see that it can answer Mr Starmer’s first argument. The thrust of the first argument is that there has been an unjustifiable refusal to apply a clear policy as to what should happen when adults are found in possession of cannabis for personal use. Turning to an allied point, it is true that Circular 18/1994 has not been amended. Circular 18/1994, however, is concerned to set out general principles. It does not focus on specific offences. It does not seem to me that the failure to amend it gives any reason to think that the policy in the Police Notice does not apply to cautions. 
99.	The context of cautioning, however, is highly relevant to Mr Starmer’s first argument and it is convenient at this point to turn to proposition (6). The concerns that underlie this proposition are concerns which I share. I accept that the court will be reluctant to intervene for breach of policy, and will only intervene for breach of policy where the policy is clearly broken. Moreover, breach of the policy does not of itself show public law error: there is no public law objection to departure from policy where there is a rational reason for the departure and no statutory obstacle. The court can intervene only if established grounds of review are shown to exist. Even then such intervention is discretionary. 
100.	That said, it seems to me that if a complaint surmounts all these hurdles it would not be right to reject it merely because the complainant is an offender. Mr Mondelly may not seem the most meritorious of claimants. As a general proposition, however, offenders are not denied the benefit of principles of public law. In this particular case, as it seems to me, the important aim of treating offenders consistently is recognised in Circular 05/2004, the ACPO Guidance, and the Police Notice. It would be contrary to that aim to deny offenders the opportunity to complain of public law error. 
101.	I find it difficult to draw a distinction between a case where a caution is administered in breach of clear general guidelines on cautioning, and a case where a caution is administered in breach of clear guidelines specific to a particular offence. Both P and Thompson fall into the former category. The principled concern which leads the public law court to intervene lies in the public interest that policy should be applied even-handedly, and departed from only if there is good reason to do so. This concern applies equally to a breach of clear guidelines specific to a particular offence. In both cases, of course, intervention for breach of policy occurs only where the breach of policy is clear. 
102.	Applying these principles, the breach of policy is clear for the reasons given earlier. Was there good reason to depart from the policy in the present case? Mr Starmer criticised specific points made by Inspector Barrett in his witness statement:
(1)	The Inspector says that the policy “does not state … that no arrest should be made for possession of cannabis”. Mr Starmer’s criticism is that this ignores the fact that the policy gives guidance as to police enforcement, including (but not limited to) arrest.
(2)	The Inspector says that the policy “does not state … that an arrest having been made, it is inappropriate to caution a person found in possession of cannabis”. Mr Starmer’s criticism is that this is a plain misconception. For reasons given earlier, the policy gives guidance as to all types of police enforcement, including the administration of a caution.
(3)	The Inspector says that a disposal of “no further action” would have been “to condone what remains a criminal offence”. Mr Starmer’s criticism is that this reasoning is wholly inconsistent with the policy. The policy itself explains the reasons why, consistently with simple possession remaining illegal, it is appropriate in most cases to do no more than seize the cannabis and give a warning.
103.	I can see no answer to Mr Starmer’s criticisms. Each of these three assertions by Inspector Barrett seems to me to demonstrate a fundamental lack of any good reason for departing from the policy. Reliance was placed on there having been a previous caution. It is unclear whether Inspector Barrett thought this brought the case within the policy. If he did, he was in my view plainly wrong, for reasons given above. If he did not, he does not proffer any rational reason for thinking that this factor warranted a departure from the policy. Paragraph 5 of his statement seems to assume that the Police Notice at paragraph 5.2 envisaged that, once somebody had been arrested, case disposal could proceed as if there were no policy. This too, to my mind, is plainly wrong for reasons given above.
104.	Is this an extreme case? The Police Notice, ACPO Guidance, and Circular 05/2004 all have consistency as an underlying aim. There was a clear breach, when administering this caution, of the policy in the Police Notice. There is a complete absence of any good reason for departing from the policy. The caution has serious consequences for Mr Mondelly. Mr Starmer’s first argument has in my view established that he has suffered real injustice. If the court can only intervene in an extreme case, I regard this case as meeting that test.
The second argument: acting contrary to the primary purpose of cautioning
105.	I can deal with this argument shortly. Mr Starmer submitted that the decision to caution did not further the aim of diverting Mr Mondelly from unnecessary appearances in the criminal court, nor was it appropriate in the light of public interest considerations. My conclusions on the first argument lead me to think that the second argument is sound. If there is indeed a distinction between a case where a caution is administered in breach of clear general guidelines on cautioning, and a case where a caution is administered in breach of clear guidelines specific to a particular offence, then the second argument may overcome that particular problem. I consider the second argument sound, however, by application of my reasoning on the first argument. The absence of good reason to depart from the policy would mean that confiscation of the cannabis and a warning would have sufficed to divert Mr Mondelly from a court appearance. It would also mean that public interest considerations had been ignored when deciding to caution. If, however, my conclusions on this basic aspect of the first argument are wrong, then I do not see any way in which the second argument could assist Mr Mondelly. I therefore say no more about it.
The third argument: cautioning in circumstances which were unreasonable
106.	This argument assumed greater importance as the oral argument developed. It assumes that the Commissioner is right to say that the policy in the Police Notice is concerned only with arrest, and not with cautions. Allowing for the public law court’s reluctance to intervene in operational matters such as cautions, and for the fact that reasonable people may hold differing views, can it be said that the administration of this particular caution was unreasonable? 
107.	Mr Starmer said that under this head he was not seeking judicial review for breach of policy. This argument assumed that in the events which had happened the policy did not expressly apply. He nevertheless submitted that when the caution was administered a stage had been reached where the police knew it had been a mistake to think that Mr Mondelly was guilty of anything other than simple possession of cannabis in his flat. Application of the policy plainly would not have led to Mr Mondelly’s arrest, let alone cautioning and the resultant criminal record, were it not for this mistake. The mistake had led to him being removed from his home in handcuffs, strip-searched, and held in a police cell from late at night until 3.30 a.m. At no time was any consideration given to whether, having realised that Mr Mondelly had been subjected to all these procedures because of a mistake, the appropriate course was to treat him in the way he would have been treated if no mistake had been made. Had this been done the only reasonable conclusion would be that administration of a caution involved a real injustice to Mr Mondelly.
108.	The answer given by Mr Beer to this criticism was that the Inspector was dealing with a series of cases in the early hours of the morning. To my mind that may explain how an injustice came to be done, but it provides no justification for it in a case like the present which involved a clear policy one of whose aims was consistency of treatment. 
109.	There may have been a desire, after putting in so much time to processing Mr Mondelly on a mistaken basis, to have something to show for it. Cautioning for a lesser offence at least achieves a result. I am not here advancing any general principle forbidding such a course. What makes that course unjust in the present case is the existence of a clear policy which Mr Mondelly was entitled to expect would have been exercised in his favour if the true facts were known. In those specific circumstances the cautioning of Mr Mondelly appears to me oppressive and unreasonable.
110.	In his oral submissions Mr Starmer identified a second aspect which raised a further important question of principle: had the decision been to charge Mr Mondelly rather than to caution him, would the circumstances of the present case have led the criminal court to stay any prosecution? A stay of the criminal proceedings may be granted where the decision to prosecute amounts to an abuse of process. It will be granted where it is necessary to stop the proceedings in order to prevent oppression. R v Adaway [2004] EWCA Crim 2831 is an example. 
111.	One objection to this argument is that a policy not to prosecute in these circumstances would be unlawful. In that regard I observe that the Police Notice rightly recognises that any decision on whether to prosecute for possession of cannabis is a matter for the Crown Prosecution Service. However in practical terms the policy on arrest means that, in general, there will be no prosecution of those who possess cannabis without there being one of the aggravating features identified in the policy. The Commissioner did not suggest that this made his policy unlawful. It would hardly lie in his mouth to do so. Nor do I consider that a judicial review challenge of a Blackburn type could successfully impugn this aspect of the policy as defying the law of the land by preventing offenders from entering the prosecution gateway. The policy and its diversion of offenders from the prosecution process find ample legal support in the rational nature of the reasons which underlie the policy and the governmental and parliamentary processes which ensured scrutiny of the aims of the policy before it was put in place.
112.	It is of course unusual that a prosecutor decides to bring proceedings contrary to policy. Nevertheless the Court of Appeal in Adaway acted in accordance with well established principles when reaching the conclusion on the facts of that case that the judge ought to have stayed the proceedings. The court must consider whether the prosecution is oppressive. For the reasons set out earlier in this judgement, I consider that the failure to apply the policy to Mr Mondelly was oppressive. 
113.	The test for exercise of the power to stay the criminal proceedings is not whether the decision to prosecute was “unlawful.” It is not necessarily right to stigmatise as “unlawful” a decision of a prosecutor to prosecute contrary to policy. As with other complaints of oppression, the legal position is that such a decision can be examined by the Crown Court or a Magistrates’ Court. If it is an abuse of power – which on any view will be an extreme case - the Crown Court can intervene by staying the proceedings. Where abuse of process directly affects the fairness of the trial the Magistrates’ Court can stay the proceedings, and in other cases it can adjourn the proceedings to enable an application to the High Court for a stay. Where the criminal proceedings are in the Crown Court, a failure by the court to intervene can be challenged by appeal to the Court of Appeal, Criminal Division. Where the criminal proceedings are in the Magistrates’ Court, a failure by the court to intervene can be challenged by an application for judicial review in the High Court. 
114.	In the present case a caution was administered in circumstances where but for a mistake by arresting officers no action would have been taken against the offender. I believe that applying established principles the court would have had strong grounds to stay the proceedings. In those circumstances cautioning involves a strong risk of injustice to the citizen. Had the ordinary course of prosecuting (rather than cautioning) been taken, the courts would have had strong grounds to intervene to ensure that the citizen would have no criminal record whatever. It is difficult to see why, merely because the police decided to caution rather than to prosecute, the citizen should have any less protection from the courts.
115.	In summary on this second aspect, if Mr Mondelly had been prosecuted rather than cautioned then he would have been able to seek a remedy against injustice by asking the courts to stay the proceedings as an abuse of process. The exceptional circumstances of this case would have given strong grounds for the appropriate court to grant a stay. In my view it is unjust that Mr Mondelly should have received a caution, and the accompanying criminal record, when if his case had gone to trial the court would have had strong grounds to stop it as an abuse of process. 
116.	I take account of warnings in earlier cases to the effect that only in exceptional cases should the court intervene in relation to the cautioning of offenders. In each of these two respects the injustice seems to me such as to render this case exceptional. 
Conclusion
117.	For the reasons given above, I would have quashed the caution administered to Mr Mondelly.

1. I take the view that we are bound by Aru ; this is a criminal cause or matter within the meaning of Section 1(1)(a) of the Administration Act 1960.

2. I would certify the following single question :-

3. Does  Metropolitan Police Notice 3/2004 render the decision to caution unlawful ?

4. I propose a costs order as suggested by the Respondent, no submissions to the contrary have been made.