In the Ammori case, the High Court held that the Home Secretary’s decision to proscribe Palestine Action under the Terrorism Act 2000 was unlawful. But a quashing order has not been issued and the government now plans to appeal. In those circumstances, are media reports correct to say that, for the time being, Palestine Action is ‘still proscribed’? And where does this leave protestors currently facing prosecution for expressing support for the organisation?
In an earlier post, I wrote about the High Court’s judgment in R (Ammori) v Secretary of State for the Home Department [2026] EWHC 292 (Admin), in which it was held that the Secretary of State’s decision to proscribe Palestine Action was unlawful, due to breaches of both domestic law and Articles 10 and 11 of the European Convention on Human Rights. At the end of its judgment, the High Court said: ‘Subject to any further representations on relief, we propose to make an order quashing the Home Secretary’s decision to proscribe Palestine Action.’ But no such order has yet been issued and the Secretary of State has now said that she plans to appeal. What, then, is the status of Palestine Action at present? If no quashing order is issued ahead of the case being decided at appellate level, does Palestine Action remain a proscribed organisation even though the High Court has held that the decision to proscribe it was unlawful?
The High Court did not itself say that Palestine Action remains proscribed, but that is how the judgment has been interpreted by others. Media outlets like the BBC have reported that Palestine Action ‘remains proscribed for now’. Meanwhile, the Metropolitan Police says that ‘expressing support [for the group] is still a criminal offence’ (under section 12 of the Terrorism Act 2000) albeit that, for now, officers will ‘focus on gathering evidence of those offences and the people involved to provide opportunities for enforcement at a later date, rather than making arrests at the time’. All of this might, however, seem counterintuitive. If the Secretary of State’s decision to proscribe Palestine Action was unlawful, how can it remain proscribed today? Is it really the case that unlawfully deciding to proscribe an organisation can secure proscription in spite of such unlawfulness — and even after that unlawfulness established through a court judgment?
A hypothetical scenario
To understand the legal position we find ourselves in, it is helpful to distinguish between two scenarios: one hypothetical, the other real. Let’s begin with the former by considering what the position would be in more straightforward circumstances in which no plan to appeal had been announced and the decision had been quashed by the High Court. The normal effect of a quashing order is to authoritatively confirm that a legal act — including an order of the type that was used to attempt to proscribe Palestine Action — is invalid. In English law, the form of invalidity in play is sometimes described as ‘voidness ab initio’, signifying that the unlawful act is void ‘from the beginning’. On this view, the quashing order does not render the unlawful act invalid: rather, it affirms that the Minister never had the power to commit the act in question, meaning that the act is not, and never has been, a legally valid one. (Another way of putting this is to say that the normal effect of a quashing order is to retrospectively invalidate an unlawful act — a formulation that captures the real-world effect of quashing but somewhat misstates the conceptual position, given that the true effect of a quashing order is merely to affirm the act’s invalidity.)
Applying that view to the Ammori case, if the High Court had issued a quashing order, the effect doing so (subject to the caveats set out below) would have been to confirm that Palestine Action had never been a proscribed organisation — from which it would follow that it could never have been a criminal offence to express support for it. This follows because section 12 of the Terrorism Act makes it an offence to invite support for a proscribed organisation or to express opinions or beliefs that are supportive of such an organisation. If the organisation has never in law been validly proscribed, support expressed before the quashing order was issued cannot constitute the offence because the organisation, never having been a proscribed one, cannot have been proscribed at the time of the alleged offence. If, for instance, the High Court had quashed the decision proscribing Palestine Action in February 2026, the implication would be that it could not logically have been an offence in autumn 2025 to express support for Palestine Action (as hundreds of protestors did): never in law having been a proscribed organisation, it could not have been such an organisation in autumn 2025. (Here, it is worth noting that the High Court referred to the prospect of quashing the Secretary of State’s decision to proscribe as distinct from the proscription order itself; however, if the decision to proscribe was unlawful, it must follow that the order itself was unlawful.)
The foregoing analysis must, however, be qualified in three ways. First, some judges have doubted the orthodox view, according to which all unlawful acts are void ab initio such that quashing orders merely affirm the invalidity of such acts, rather than rendering them invalid. A prominent example of such departure from orthodoxy can be found in the judgment of Lord Reed in R (Majera) v Secretary of State for the Home Department [2021] UKSC 46, in which he doubted the orthodox account set out above. In doing so, he contradicted the approach he had previously taken in R (UNISON) v Lord Chancellor [2017] UKSC 51, in which he said that regulations that were unlawful because they breached a constitutional right were necessarily ‘unlawful ab initio, and must be quashed’.
In Majera, Lord Reed was concerned, among other things, with the ‘administrative inconvenience’ that might attend a strict application of the concept of invalidity, and this led him to argue that in some circumstances, unlawful acts ought not to be treated as void ab initio. That a blanket rule of voidness ab initio can produce inconvenient outcomes in some circumstances is unarguable, but two points can be made in response to Lord Reed’s approach to this. On the one hand, as other judges have acknowledged, there are ways of managing this issue other than denying the conceptual voidness of unlawful acts. On the other hand, even on its own terms, Lord Reed’s approach — that voidness ab inito should sometimes be finessed away in the interests of administrative convenience — seems wholly inapposite in the context of Ammori. After all, that case concerns the potential criminal liability of hundreds of people charged with supporting an organisation that, according to the High Court, is not in the first place proscribed. In such circumstances, it would be monstrous if the rule of law was subordinated to administrative convenience by treating the proscription order as anything other than void ab initio.
A second qualification to the orthodox position arises thanks to section 29A of the Senior Courts Act 1981. It says that a quashing order issued by a court ‘may include provision … removing or limiting any retrospective effect of the quashing’. Section 29A is important for two reasons. In the first place, when a court makes such provision, the effect is to ‘uphold’ the unlawful act, meaning that ‘it is to be treated for all purposes as if its validity and force were, and always had been, unimpaired by the relevant defect’. This amounts to statutory recognition of the correctness of the orthodox view: that the normal effect of a quashing order is retrospective, and that the normal effect of legal defects is to impair the validity of administrative acts and orders. (On this view, if a court removes or limits retrospective effect using its section 29A power, this amounts to a statutorily mandated closing of the eyes to an underlying conceptual reality that remains undiminished.)
In the second place, the foregoing point notwithstanding, section 29A might seem to suggest that if a quashing order is eventually issued in relation to Palestine Action, it could be denied retrospective effect, thereby leaving intact the criminal liability of those who have already been charged with the section 12 offence. (This would follow because if the decision to proscribe was quashed only prospectively, courts would be required to treat Palestine Action as if it had been proscribed up until the quashing order was issued.) That, however, seems unlikely. Section 29A goes on to say then when deciding whether to remove a quashing order’s retrospective effect, courts must consider (among other things) ‘the interests or expectations of persons who would benefit from the quashing of the impugned act’ and ‘any detriment to good administration that would result from exercising or failing to exercise the power’. In the Palestine Action case, it is very difficult to see how any reasonable judge could conclude that ‘good administration’ requires an unlawful order to be treated as if it were retrospectively valid when that would have the effect of criminalising enormous numbers of individuals who had sought to exercise their right to peaceful protest. Such a judicial conclusion would be an affront to the rule of law.
Third, it is widely recognised that unlawful acts can and do produce consequences in the real world, even if they are conceptually invalid. Until a court has determined that an act is unlawful, most people, including the authorities, will proceed on the basis that it is lawful and valid. Prior to the High Court’s judgment, for instance, it is unsurprising that the police arrested protestors for supporting a proscribed organisation, given that they could not have known that the High Court would later rule that the underlying proscription order was invalid. When the true position is revealed in such cases, the risk may arise of a ‘domino effect’, the unlawfulness of an original act (here, the proscription order) impacting upon myriad other matters (such as the criminal liability of the protestors). There are various ways (without denying the underlying conceptual voidness of unlawful acts) in which courts have, in the name of administrative convenience, sought to insulate subsequent acts from what turns out to be the invalidity of predecessor acts on which they seem to depend. The most conceptually convincing technique is the ‘second actor theory’ developed by Christopher Forsyth (‘“The Metaphysic of Nullity”: Invalidity, Conceptual Reasoning and the Rule of Law’ in Christopher Forsyth and Ivan Hare (eds), The Golden Metwand and the Crooked Cord: Essays in Honour of Sir William Wade QC (Oxford: Oxford University Press, 1998)) and endorsed by the Appellate Committee of the House of Lords in Boddington v British Transport Police [1999] 2 AC 143.
On that view, in some situations an act that appears to be valid but which is actually invalid is sufficient to form the legal foundation for subsequent action. On this approach, the appearance of a valid proscription order might well be sufficient to trigger the police’s powers to arrest those who are, at the relevant time, committing an offence like the section 12 offence. But to extend such an approach to impose criminal liability on protestors charged with section 12 offences would, like the other potential routes around voidness ab initio canvassed above, raise profound rule-of-law concerns. Indeed, to allow criminal liability to be imposed on individuals by way of unlawful administrative orders would imply a descent into authoritarianism. It is for precisely that reason that English law allows the unlawfulness of such orders to be pleaded collaterally as a defence in criminal proceedings — irrespective of whether they have been quashed. The better view, therefore, is that the criminal liability of the protestors must stand or fall with the validity of the proscription order.
The situation today
The situation described above — in which a quashing order would likely retrospectively invalidate the proscription order, relieving the protestors of criminal liability — is not, of course, the one we currently find ourselves in. What, then, is the position at present, in the absence of a quashing order? The Supreme Court considered the same conceptual question, albeit in a different context, in Ahmed v HM Treasury (No 2) [2010] UKSC 5. Having held in a precursor case that secondary legislation freezing terrorists’ assets was unlawful, the court declined a request from the Treasury to suspend the quashing order it proposed to make (so avoid any gap in the freezing process while the government brought forward fresh legislation). The court reasoned that unlawful government acts are ‘of no effect in law’ and that the purpose of quashing them is simply ‘to make it quite plain that this is the case’. This reinforces the linguistically paradoxical, but theoretically inevitable, point that quashing orders do not ‘quash’ unlawful acts; rather, they highlight legal flaws that makes quashing them conceptually unnecessary even if it remains practically useful (and sometimes essential). It followed, said the court, that withholding a quashing order would convey a misleading impression by wrongly suggesting that, while unquashed, an unlawful act was valid. The court, said Lord Phillips giving the majority judgment, ‘should not lend itself’ to such ‘obfusact[ion]’ of the true effect of its own judgment.
On this view, once a court has concluded — as the High Court did in Ammori — that a given act is unlawful, the orthodox view, powerfully endorsed by the Supreme Court in Ahmed (No 2), suggests that withholding a quashing order makes no conceptual difference. The absence (for now, at least) of a quashing order notwithstanding, the High Court has already determined that the proscription order was unlawful, meaning that, on the orthodox view, it is void ab initio. Does this mean that it would be lawful for someone to express support today for Palestine Action, or would they still commit an offence under section 12 of the Terrorism Act such as ‘inviting support’ for a proscribed organisation or expressing ‘an opinion or belief’ that is supportive of such an organisation? It would certainly be very unwise for anyone to proceed on the basis that Palestine Action remains anything other than a proscribed organisation, and nothing in this post should be taken to suggest otherwise. The most that can be said for now is that an authoritative view has been expressed by the High Court that the proscription order is unlawful; that the orthodox implication of such a judicial conclusion is that the order is and always has been invalid; and that the normal consequence of such an order being invalid is that it cannot serve as a foundation for an offence such as the section 12 offence, which requires support to be invited or expressed for an organisation that was lawfully proscribed at the time of the alleged offence.
In due course, an appellate court might agree with the High Court’s conclusion and issue a quashing order, which, for the reasons set out above, we would normally expect to be fully retrospective in effect, meaning that Palestine Action had never been a proscribed organisation and that inviting support for it had never been a criminal offence. But it is also possible that an appellate court might disagree with the High Court by ruling the proscription order to be lawful. In those circumstances, the High Court’s judgment notwithstanding, the proscription order would be — and would always have been — valid. That, in turn, would mean that ever since the order was made, it would have been an offence to invite or express support for Palestine Action. Those who have already been charged with offences under section 12 will therefore find themselves in a period of unavoidable uncertainty until the appeal process has been concluded: we simply cannot know whether the High Court’s view will turn out to be the right one, the ‘right’ view, for present purposes, being that which is eventually reached by the most senior appellate court to address the issue.
Finally, what about anyone who is currently contemplating inviting or expressing support for Palestine Action? Is it a criminal offence to do so at the present time? The Metropolitan Police says so. But if, as the the High Court says, Palestine Action has not validly been proscribed, how can supporting it amount to the offence of supporting a proscribed organisation? The answer is that it cannot amount to the offence if the High Court is correct — but we will not know if the High Court is correct until the appellate process has run its course. Palestine Action might turn out, following completion of that process, never to have been a proscribed organisation. But it might equally turn out to have been one all along, in spite of the High Court’s contrary view. Anyone who today invites or expresses support for Palestine Action therefore runs the risk that if an appellate court disagrees with the High Court, the section 12 offence will have applied in respect of Palestine Action without interruption since the original imposition of the proscription order on 5 July 2025.
Views differ about whether Palestine Action should be proscribed and whether, as a result, it is right to criminalise large numbers of individuals who have engaged in peaceful protest. Indeed, on one view, advanced by former Supreme Court Justice Lord Sumption, it is the very connection between those two matters that is the problem, the section 12 offence of supporting proscribed organisations having been, in his view, framed much too broadly. It is, he argues, ‘a blot on English criminal law’ that those who merely stood in Parliament Square expressing support for Palestine Action should now be subject to prosecution. Whether it will be possible successfully to prosecute them now turns on whether Palestine Action is — and was — a proscribed organisation, precisely because the criminalisation of peaceful protest by section 12 of the Terrorism Act depends on whether, in the first place, the organisation in question has been lawfully proscribed. It is for that reason that the fate of protestors charged with expressing or inviting support for Palestine Action now turns upon whatever conclusion an appellate court eventually reaches about the lawfulness of the proscription decision itself.
This post draws upon ideas set out in Mark Elliott and Philip Murray, ‘In Defence of Classical Administrative Law’ [2026] Cambridge Law Journal (forthcoming), although I take sole responsibility for the views set out in this post. A pre-publication copy of the article can be found here. This post is not intended to be a source of legal advice and nothing in it should be relied on as such.
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