LORD JUSTICE KEENE: This appeal arises out of events surrounding the construction of a research laboratory by Oxford University ("the University") in South Parks Road, Oxford. When built, the laboratory may, it seems, be used in part for experimentation on living animals. Such experimentation is intended to conform with the statutory regulation applicable to it and would be a lawful activity. Likewise, the construction of a laboratory itself is a lawful activity. Nonetheless, the proposed experimentation, and hence the construction process, have given rise to vigorous opposition amongst those who consider it immoral to experiment on living creatures. That is of course a view which they are fully entitled to hold.

Some of those who oppose the works seek to protest and to make their views known in a lawful fashion, exercising their undoubted right to freedom of expression whereby they are entitled to seek to persuade others of the rightness of their views. Other opponents have not abided by the law but have resorted to intimidation, criminal damage and other unlawful acts. Some flavour of these unlawful activities can be found from paragraphs 27 and 28 of the judgment of Grigson J in these proceedings, dated 10 November 2004.

On 19 July 2004 a number of contractors involved in the construction project determined their contracts and for a time work on the project ceased. This seemed to echo what had happened in Cambridge, where a campaign to stop the construction of the research laboratory had been successful. In these circumstances, the University and others involved in the project began proceedings against a number of defendants in September 2004. Some of those defendants were individuals and others were unincorporated associations.

For present purposes the history of the proceedings can be summarised very briefly.

The claimants, now the appellants, sought and obtained interlocutory relief, first without notice and then, on 10 November 2004, following an inter partes hearing before Grigson J. His order continued the injunction and banned protest activities within an exclusion zone, save at an identified location on Thursday afternoons, and prohibited the photographing of protected persons, so-called, broadly speaking those engaged on the construction project. However Grigson J accepted a personal undertaking by the first defendant, Mr Broughton, in similar terms to the injunction which in consequence was not imposed on him.

The injunction was varied by Calvert-Smith J after a without notice hearing on 6 March 2006. Amongst other things, the variations included Mr Broughton amongst those bound by the injunction. There was then an inter partes hearing before Holland J on 10 and 11 April 2006. He set aside the order of 6 March 2006 in so far as it subjected Mr Broughton to the injunction because it had been made in his absence. The judge noted that the undertaking given to Grigson J continued. Beyond that, Holland J made an interim order pending a carrying out by him of a view of the area involved. His interim order generally continued the injunction, but also banned the use of noise amplification equipment, save for the use of a megaphone between 1.00 and 2.00 pm on Thursdays. Mr Broughton gave an undertaking to like effect.

The matter then came back before Holland J after a view of the site. In a careful and generally detailed reserved judgment dated 26 May 2006, he increased the size of the exclusion zone and also prohibited all noise amplification devices within a wider area, save when used in connection with a lawful, peaceful procession or assembly not more than once a month. The detailed terms of his order of 26 May 2006 are a matter of record and it is unnecessary to set them out in this judgment, except to emphasise that the order remained an interlocutory one effective until trial or further order.

This appeal is not concerned with most of the matters upon which Holland J pronounced. The University and other claimants appeal with the permission of Scott Baker LJ against two somewhat limited aspects of the judge's decision of 26 May. The first concerns the position of Mr Broughton who, as I have said, is the first defendant. The judge said (paragraph 33 of his judgment) that "with some hesitation" he was content to accept an undertaking from Mr Broughton so long as it reflected the terms of the order being made against the other defendants. Such a course had been opposed by the claimants, the present appellants. They had not opposed the acceptance of an undertaking by another individual defendant, Mr Cogswell, but they did oppose it in Mr Broughton's case and they now appeal again the judge's decision in that respect.

The other point which arises in this appeal concerns the judge's decision to strike out the statement of case as against the 12th defendant, Greg Avery. The judge did so under CPR 3.4.2(b), that is to say, on the basis that it would be "likely to obstruct the just disposal of the proceedings" (see paragraph 13 of the judgment).

Again the judge said that he acceded to the application to strike out "with more hesitation" than he did in respect of two other defendants. The appellants now contest that part of his decision also.

The context for considering both these matters must include the appellant's claim in the proceedings against these two respondents, Mr Broughton and Mr Avery. In their amended form, the particulars of claim seek injunctions and damages under the Protection from Harassment Act 1997 ("the 1997 Act") and for conspiracy and nuisance. The 1997 Act provides by section 1(1) that:

Section 2(1) makes such a course of conduct a criminal offence, subject to certain statutory defences to be found in section 1(3). However, a breach of section 1 may also be made the subject of civil proceedings by any person who is or may be the victim. Furthermore, and of relevance for present purposes, other provisions in section 3 deal with the situation where an injunction has been granted to restrain a person from conduct amounting to harassment. Thus, sections 3(3) and 3(5) give the court the power to issue a warrant for the arrest of such a person if there are reasonable grounds for believing that he has broken an injunction. Section 3(6) is particularly significant. It makes it a criminal offence to break such an injunction without reasonable excuse.

The 1997 Act provides that where a person is convicted of a section 3(6) offence, he cannot then be punished for contempt of court for the same conduct; the converse position is also covered (see section 3(7) and (8)). However a number of points would seem to flow from these provisions. First, it is to be deduced that Parliament in 1997 took the view that in cases falling within those provisions a further remedy was required in addition to the already existing one of proceedings for contempt of court when an injunction had been broken. Secondly, the criminal offence under section 3(6) only arises where an injunction is broken without reasonable excuse. No such offence occurs when an undertaking to the court given in civil proceedings under the 1997 Act is broken. Thirdly, a police constable has a power of arrest without warrant where a person is about to commit, or is in the act of committing, an offence (see section 24(1) of the Police and Criminal Evidence Act 1984 as amended by the Serious Organised Crime and Police Act 2005).

So far as the issue in respect of Mr Broughton is concerned, the appellants contend that the judge wrongly exercised his discretion in refusing to grant an injunction and in accepting Mr Broughton's undertaking. Mr Flint QC, who appears for the appellants, draws attention to the judge's own comments in his judgments about Mr Broughton's conduct which, it is said, shows that Mr Broughton had not abided by the undertaking which he had given to Grigson J. In his judgment of 11 April 2006, Holland J referred to a DVD exhibited by the appellants, being a compilation of material filmed of protests against the Oxford project. The judge accepted that this material showed Mr Broughton delivering what he called a "fiery address" on 14 January 2006 in terms

Mr Flint submits that, in his decision of 26 May 2006, Holland J failed to take into account this evidence of breaches by Mr Broughton of his undertaking and failed to reflect the importance of an injunction in proceedings brought under the 1997 Act. It is said that this action on the part of the judge put Mr Broughton into a privileged position as compared to other defendants covered by the injunction: they would be liable to arrest for a breach of the injunction, whereas he would not be so liable for breach of his undertaking. Moreover, it is argued that the judge failed to give any reasons for rejecting the appellant's objections to an undertaking being accepted. This, Mr Flint submits, is itself enough to vitiate the judge's exercise of discretion, because one cannot see whether he took into account the appellant's arguments about the different regime applicable under the 1997 Act for those subject to an injunction from that applicable to a person who has only given an undertaking, or, if the judge did take it into account, why he rejected those arguments. Consequently, this court can and should exercise its own discretion.

Proceedings for contempt of court are, it is said, no substitute for the more extensive powers available when an injunction is in force. Contempt proceedings, argues Mr Flint, are essentially retrospective and require clear evidence before they can be effective. The protection afforded to the University by the existence of an injunction is much more effective. Section 3(6) of the 1997 Act allows the police to act at the time by arrest or by warnings; it therefore operates as a deterrent against the prohibited conduct. Holland J was wrong in principle to reject an injunction in respect of Mr Broughton and this court should extend the injunction granted against others to cover him as well.

In response, on behalf of Mr Broughton, Miss Harrison emphasises the discretionary nature of the judge's decision on this aspect of the case. In such a situation this court should only interfere when the decision falls outside the generous scope of the proper exercise of discretion. Even in proceedings under the 1997 Act, the court still has a discretion to accept an undertaking. Miss Harrison argues that one can discern the judge's reasons for refusing an injunction if one reads his April judgment together with that of 26 May. In paragraph 13 of the earlier judgment, he emphasised that courts take undertakings and breaches thereof seriously, and he referred to there having been a shot across the bows in Mr Broughton's case. The judge appeared to have regarded the words spoken by Mr Broughton at the demonstration of 14 January 2006 as words spoken in the heat of the moment, and the judge was aware that there had been increased cooperation over the organisation of the demonstrations. In those circumstances, he was prepared to give Mr Broughton the benefit of the doubt.

Having said all that, Miss Harrison concedes that the judge makes no reference anywhere in his judgment to section 3(6) of the 1997 Act or to the difference in the two regimes of injunction and undertaking. On the exercise of discretion generally, it is contended that the judge cannot be said to have erred. Apart from the matters already mentioned, Miss Harrison emphasises that the judge heard evidence and argument over several days and conducted views of the area. He was in a much better position than this court to weigh up the pros and cons of an injunction. Though there are different ways of enforcing an injunction and an undertaking, given the 1997 Act, both, it is said, can ultimately lead to imprisonment. Miss Harrison argues that what is significant is that the University have brought no proceedings against Mr Broughton for contempt; it has not used the remedy available to it, nor has it reapplied to the judge for an injunction. Moreover, even where there are injunctions in force against a number of the defendants, there have been no prosecutions and no arrests for breach of the injunction.

I note that as a matter of fact that last point does not appear to be accurate. Mr Flint has drawn our attention in reply to the evidence that there have been two arrests on such a basis on 17 and 21 December 2005 respectively, according to evidence of the senior police officer involved in these matters, Superintendent Shead. There does, however, seem to have been no prosecutions.

I propose to deal with the arguments about this first issue concerning Mr Broughton before turning to the submissions about Mr Avery. I accept Miss Harrison's point about the need for this court to be slow to interfere with the exercise of discretion by a first instance judge. That is trite law. The principles were set out by Lord Woolf MR in AEI Rediffusion Music Limited and Phonographic Performance Ltd [1999] 1 WLR 1507 at 1523 as follows:

In the present case the court can perhaps be a little less reluctant to intervene, given the judge's own express hesitation about the right outcome of this dispute. Of course, what the passage I have just quoted pre-supposes is that one can readily identify what the judge has or has not taken into account. That is one of the problems in this case. What, for my part, I find striking about this part of the learned judge's otherwise very detailed and careful decision is the complete absence of any reference to the unusual situation which obtains under the 1997 Act. I say unusual, because in most civil litigation the court will tend to regard the effect of an undertaking as equivalent to that of an injunction: if the undertaking is broken, the party in breach is in contempt of court just as he would be if he had been in breach of an injunction.

It may be that that was the basis upon which the judge here approached this aspect of the case, although it is far from easy to see, because Mr Flint is right to say that the judge does not expressly give his reasons for rejecting the appellants' case on this issue. What is clear is that the judge makes no reference to the difference under the 1997 Act between a person bound by an injunction in such proceedings and one who is bound only by an undertaking to the court. I find it impossible to say whether the judge took this factor into consideration at all.

Miss Harrison has done a valiant job this morning in trying to spell out the judge's reasons for refusing an injunction and rejecting the university's arguments where Mr Broughton is concerned, but I do not find her attempts persuasive. Thus, the statement by the judge that the court should take undertakings seriously does not provide any rational basis for rejecting the university's arguments about the different regimes applicable.

The absence of reasons in his judgment on this issue means that this court is entitled to exercise the discretion afresh, as does his apparent failure to take into account the different regimes to which I have referred. We must, in my view, approach the matter afresh.

The difference to which I have referred seems to me to be of importance. Superintendent Shead in his witness statement refers to the value to his officers of the injunction where it exists (see paragraph 2) and to the difference in Mr Broughton's position because he was not subject to the injunction (paragraph 113). One also sees from paragraph 6 of that witness statement that the police officers are able to give warnings where the person concerned is subject to the injunction and is about to breach it, because a breach would be a criminal offence. So in most, though not all, cases the police can stop short of actual arrest so long as a warning is effective. Nonetheless, that power of arrest is a powerful, and to my mind appropriate, sanction always existing in the background when an injunction is in force under the 1997 Act.

True it is that ultimately there is always the possibility of imprisonment for contempt even where there is only an undertaking in existence. But that is always a last resort. It is the power of arrest which is so important in cases of the kind with which we are dealing, which have a public order element in them.

To that consideration I would add the further factor of Mr Broughton's past conduct. There is evidence of a breach, even possibly breaches, by him of the undertaking which he had given to Grigson J, particularly at the meeting on 14 January 2006. The judge seems to have attached weight to the fact that no contempt proceedings had followed. That, however, does not render this factor irrelevant. The evidence indicates that Mr Broughton did not regard the undertaking as being of sufficient significance to induce him to comply with its terms and to avoid unlawful conduct. Having read the papers with some care, it seems to me that there could be little doubt that he is a leading light in the campaign against the building of the laboratory. There is nothing wrong with that. If conducted lawfully, that campaign was not to be criticised, but it is important that it should be conducted lawfully.

For the reasons I have given I, for my part, have concluded that an undertaking was quite inappropriate here; an injunction should have been granted. On that basis I would on this issue allow the appeal and vary the judge's order accordingly.

I turn to the other issue, the striking out of the statement of case against Mr Avery under CPR 3.4.2(b) as something which would be likely to obstruct the just disposal of the proceedings. What Holland J said on this part of the case can be found at that part of paragraph 13 of his judgment where he dealt with Mr Avery, the 12th defendant. Having referred to the fact that Mr Avery was an admitted participant or a supporter of Stop Huntingdon Animal Cruelty (SHAC), the judge said:

It seems that the principal reason behind the judge's decision to strike out was that Mr Avery was already covered by the order against SHAC, of which he is said to be a founder member, and so the strike out was justified so as to avoid a proliferation of parties. I note that what is meant by "obstruct" in that provision in the Civil Procedure Rules has been said to be "impede to a high extent" (see Atos Consulting Ltd v Avis Europe plc [2005] EWHC 982. As a matter of principle, the use of the strike out weapon by the court in respect of an otherwise properly maintainable claim should be a matter of last resort.

For the appellants, Mr Flint submits that the judge was wrong to rely on this provision because it had not been advanced in the course of argument. Furthermore, it is said, the judge appears to have overlooked the fact that the appellants were not merely seeking an injunction against Mr Avery but were also seeking damages against him. The mere fact that he was and is a member of SHAC, one of the other defendants in the claim, provides no proper substitute for a claim against him personally because a judgment against SHAC in damages could only be enforced against Mr Avery personally with the court's permission under CPR 19.6(4)(b). So the fact that he may be bound by the interlocutory order against SHAC, an unincorporated association, does not have the significance attached to it by the judge. Moreover, only if he is a party to the proceedings can the appellants obtain disclosure against him as a matter of right.

The appellant also emphasise the fact that there is evidence that Mr Avery has been prominent in the campaign against the laboratory. The evidence shows, says Mr Flint, that Mr Avery has incited others to take unlawful action. At the meeting on 14 January 2006 he was videoed saying the following:

It is acknowledged by the appellants that Mr Avery has been made bankrupt, but it is emphasised that this present claim is one made against him personally, not against his trustee in bankruptcy. The conduct in question indeed post-dates his bankruptcy. Overall, it is submitted that no obstruction to the just disposal of the proceedings would result from allowing the claim against Mr Avery to proceed.

For his part Mr Avery, who has appeared in person today, stresses his own bankruptcy. He also argues that disclosure in other proceedings, those brought by Huntingdon Life Sciences, produced nothing of value. Mr Avery says that the evidence against him is thin, being his one speech at the 14 January demonstration where feelings ran high because the police did not abide by what they had previously agreed. In any event, by referring to getting "tools" and to "smashing Oxford University", he was not advocating any illegal action. The tools he had in mind, he tells us, were banners and megaphones.

I am bound to say that I find that last argument disingenuous. Listeners to that speech were most unlikely to have interpreted it in that benign way and it is impossible to accept that that was what was intended. In any event, Holland J did not strike out the claim against Mr Avery under CPR 3.4(2)(a), that is to say because the statement of case disclosed no reasonable grounds for bringing the claim. He struck it out under CPR 3.4(2)(b) as likely to obstruct just disposal. It seems, as I have indicated already, that he was anxious to avoid an unnecessary proliferation of parties.

That is a proper and indeed commendable objective to bear in mind. However, it does not, in my view, justify striking out a claim against a person who, on the evidence, appears to have taken a relatively prominent role on at least one occasion merely because he is also represented by an unincorporated association already joined as a defendant. The relationship in the litigation between the appellant and Mr Avery is very different if he is a personal defendant from that which would exist if he is merely sued as part of SHAC. The points made by Mr Flint about damages and about discovery, to which I have referred earlier, seem to me to be valid ones. Conversely, I cannot accept that leaving the claim against Mr Avery in place would impede to a high extent the just disposal of the proceedings. It seems to me that the judge erred in deciding to strike out the claim.

I would therefore allow the appeal on this aspect of the case also.

LORD JUSTICE WALL: I agree that this appeal should be allowed. I add a short judgment of my own out of respect for Miss Harrison's able argument on Mr Broughton's behalf.

For my part, I agree with Miss Harrison that in accepting an undertaking from Mr Broughton in the same terms as the injunction granted against the other defendants, the judge was exercising a judicial discretion, which can only be impugned in this court on well-known and clearly identified criteria. One such criterion, however, is a failure by the judge to take a material factor into account; another is a failure properly to explain the reasoning by means of which he has reached a given conclusion. The two of course may equally operate in conjunction.

Miss Harrison argues that the terms of section 3(6) of the 1997 Act and the remedy available under it were clearly in the judge's mind. She says that he was aware of the distinction between the remedy open to the University by way of application to commit for the breach of an undertaking, as well as the alternative remedy of arrest for breach of an injunction open to the police. Differences in enforcement, she argued, do not and should not affect the exercise of discretion. The judge, she submitted, was anxious to contain the demonstrators' activities within lawful bounds: he thought the best way of doing so was to seek to engage the cooperation of Mr Broughton by means of an undertaking. She points to the analysis of his behaviour by the judge in paragraphs 8 to 13 of the judgment of 11 April 2006 and argues from that that it was open to the judge an 26 May, having taken that behaviour into account, and as an exercise of judicial discretion, not to impose an injunction on him, but to allow Mr Broughton's conduct to continue to be governed by his undertaking. Miss Harrison accordingly submits that the reason for this approach are further explained by the judge in paragraph 35 of the 26 May judgment, in which he describes what he called, overall, the "conscious effort on the part of protesters to understand and heed Court orders". He identifies what he describes as "good evidence that co-operation with the Police is growing on the basis of mutual trust" and that "all can pay tribute to the Force's determination to act even-handedly." That paragraph then concludes with this passage:

I have carefully considered whether the two judgments as Miss Harrison argues, taken in combination, are sufficient to meet Mr Flint's argument that the judge has explained neither his analysis of section 3(6) nor his reasons for an exercise of discretion which does not engage it. I have come to the clear conclusion, with all respect to the judge, that they are not. This was a considered judgment: the section 3(6) point had been put before him in argument and was clearly critical to his decision. Whilst I understand the approach which the judge was attempting to adopt, I am of the clear view that the two judgments, even taken in combination, fail to address the critical point. Since it goes to the heart of the exercise of his discretion, and a clear response to the argument relating to section 3(6) is absent from either judgment, it is equally clear, in my view, that his exercise of discretion is vitiated, and thus cannot stand. It thus falls to this court, under well-established principles, to exercise its discretion afresh.

In these circumstances, like my Lord, it is my clear view that the judge should have imposed an injunction. In particular, it is clear to me that the amendments to the Protection of Harassment Act introduced by the Serious Organised Crime and Police Act 2005 give these proceedings a public order dimension absent from ordinary civil litigation, which makes it wholly appropriate, in my view, for the police to be given the necessary power to arrest any party governed by the injunction who is in breach of it. In my judgment, this aspect takes the case out of the category of conventional private litigation between individuals in which the onus to prove a breach lies on the party immediately affected by it. In my judgment, the imposition of an injunction will not adversely affect Mr Broughton if his conduct continues to be within its terms. There is no danger of double jeopardy. But if he strays outside it, I see no reason why, for the reasons advanced by Mr Flint, the obligation should be on the University to prove contempt. I equally see no reason why the imposition of an injunction should affect Mr Broughton's capacity to cooperate with the police in the manner which the judge has identified.

For these reasons, in addition to those given by my Lord, I would, like him, allow the appeal. I have nothing I can usefully add to what my Lord has said in relation to Mr Avery, save to say that I agree with it.

LORD JUSTICE WILSON: I agree that both limbs of this appeal should be allowed for the reasons given by my Lord, Keene LJ, supplemented in the case of Mr Broughton by the reasons given by my Lord, Wall LJ.