The UK Supreme Court began hearing arguments on Wednesday in a case that has become far more than a dispute over one activist group. Huda Ammori, co-founder of Palestine Action, is challenging the Home Office’s decision in July 2025 to proscribe the group under the Terrorism Act 2000, a designation that placed it alongside al-Qaeda and Boko Haram and criminalised membership and expressions of support, with some offences carrying up to 14 years in prison.
The five justices are not being asked whether Palestine Action’s tactics were lawful or whether its members caused damage. They are being asked whether banning a protest organisation under terrorism legislation is compatible with the European Convention on Human Rights, specifically the rights to freedom of expression and association. Ammori’s legal team told the court that Palestine Action is the first of 98 proscribed organisations to be banned solely for serious damage to property. The answer will shape how Britain treats political protest for years to come.
The core of Ammori’s legal argument is that the government used a sledgehammer to crack a nut. Her barrister, Raza Husain KC, told the court that the Home Secretary’s own advisers had assessed only three of the 385 actions carried out by Palestine Action over five years as meeting the legal definition of terrorism, less than one per cent. Those three actions were deemed terrorist, Husain said, because they involved “serious damage to property”, not because anyone was killed or injured.
The vast majority of the group’s activities, Husain argued, consisted of graffiti, petty vandalism, occupation, and lock-ons, tactics that the state has ample criminal law to address without resorting to counter-terrorism powers. Henry Blaxland KC added that proscription had not deprived Palestine Action of publicity or discredited its brand; all it had done, he said, was “to pour fuel on to a fire of one of the most publicly-contested issues of our time”, and the ban was “disproportionate” and “completely unnecessary”. Ammori’s team also drew a historical parallel that the Court of Appeal had previously rejected: the suffragettes, they argued, used tactics similar to, or more extreme than, Palestine Action’s, including a bombing campaign, yet they are remembered as heroes of democratic progress rather than terrorists.
The Home Office’s defence rests not on the statistical rarity of terrorist-defined acts but on the trajectory of the group’s campaign, and it says the Court of Appeal made no legal error. Sir James Eadie KC, for the government, told the justices that the Court of Appeal had rejected Ammori’s attempt to portray Palestine Action as a “non-violent direct action protest group”, and that the ban does not prevent “vocal large-scale and frequent expressions of support for the pro-Palestinian cause”. He pointed to the August 2024 raid on Elbit Systems’ premises at Filton, near Bristol, which the Home Office says caused an estimated £1 million in damage, and the June 2025 break-in at RAF Brize Norton, where activists are accused of spraying red paint over two Voyager aircraft; five people have pleaded not guilty and are due to stand trial in January 2027. The Home Office also cites the fracturing of a police officer’s spine with a sledgehammer during the Filton raid, for which one activist, Samuel Corner, was convicted of grievous bodily harm and jailed, although Ammori’s lawyers told the court the group had never advocated such violence.
A coalition of Jewish groups, including the Jewish Leadership Council and the Community Security Trust, was granted permission to intervene. Their barrister, Adam Wagner KC, said in written submissions that Britain’s Jewish community is “especially vulnerable to Palestine Action’s violent activities” and that lifting the ban would “re-arm and revitalise a sinister and dangerous movement”. The groups argued that Palestine Action showed an “escalating trajectory of seriousness” and an “expanding focus” that had moved beyond targeting defence firms. The Court of Appeal, which had refused the two groups permission to intervene in that hearing, upheld the ban in June, overturning a February 2026 High Court ruling that it was unlawful and disproportionate and finding that the proscription was a “justified and proportionate” interference with free expression.
Whatever the legal merits, the ban has been enforced on a scale British terrorism law has not seen before. More than 4,000 people have been arrested in connection with support for Palestine Action since proscription, according to Home Office figures seen by the BBC. By Reuters’ count, the arrests made up to June alone account for more than a third of all terrorism arrests in Britain since 9/11. Many of those arrested were older protesters: during one demonstration in August 2025, 532 people were arrested, including 259 aged 60 or older and almost 100 in their 70s, according to Metropolitan Police figures. On Wednesday alone, the Metropolitan Police said 27 people were arrested outside the Supreme Court on suspicion of displaying support for a proscribed organisation. Among the protesters was the actor Alfred Enoch, who carried a placard reading “this is democracy not terrorism”; ITV News and Jewish News reported he was not arrested, while Middle East Eye reported that he was.
Amnesty International UK described the arrests as evidence of the “chaos wrought by the government’s grave misuse of terrorism powers” and “how dangerously vague our terrorism laws are”. Ammori’s lawyers told the court that the ban had triggered a “crisis in confidence” in counter-terrorism law itself, turning law-abiding citizens into defendants and clogging the courts with prosecutions whose legitimacy is now in doubt. More than 1,200 charges have been authorised, according to the BBC, but those trials are in limbo pending the outcome of this case.
The legal path to reclassification is narrow, but it exists. After the Court of Appeal reversed the High Court’s ruling in June, the Supreme Court granted Ammori permission to appeal on a single ground: whether the proscription is compatible with the European Convention on Human Rights. If the justices find that the ban fails the proportionality test, that it interferes with speech and association more than is necessary to achieve a legitimate aim, they can quash the proscription and the group would no longer be classified as a terrorist organisation.
That outcome is far from certain. The Court of Appeal has already endorsed the government’s view, and to win, Ammori must persuade the justices that the Court of Appeal got the proportionality balance wrong. But the political and social context has shifted since June. The sheer scale of arrests, the criticism from groups including Amnesty International UK, the intervention of PEN International and English PEN, and the spectacle of elderly protesters being charged with terrorism offences have created an environment in which the government may face pressure to revisit the designation even if it wins in court.
Home Secretary Shabana Mahmood could use her statutory powers to deproscribe the group. Deproscription is rare, and was most recently used for Hay’at Tahrir al-Sham in October 2025; the political cost of appearing soft on terrorism would be considerable. A more likely scenario, if the ban survives, is that the government quietly narrows the scope of prosecutions or issues guidance to police to reduce the number of arrests, a de facto softening rather than a formal reclassification. But the longer the case drags on, the harder it becomes for ministers to defend a designation under which people in their 70s have been arrested as terrorism suspects and more than 1,200 charges sit in limbo.
If the justices uphold the ban, they will confirm that the Home Office can use terrorism legislation against protest movements whose tactics cause serious property damage, a precedent that could, in principle, be applied to climate activists, anti-war campaigners and others. If they quash it, they will set a limit on how far counter-terrorism powers can reach into protest, however disruptive.
Whatever the outcome, the ban on Palestine Action has become a test of whether the UK’s counter-terrorism architecture is a proportionate tool for protecting the public or an instrument for suppressing unpopular speech.