In July 2025, the UK government banned Palestine Action, a non-violent direct-action network, as a terrorist organisation. Many called it “unprecedented”. But was it? A longer view suggests the decision sits at the end of a decades-long widening of what the state counts as “terrorism”.

Early counter-terror rules grew out of empire. In 1919, Westminster passed the Anarchical and Revolutionary Crimes Act in India, allowing detention without trial. A similar law soon followed for Ireland. In the 1970s, UK policy hardened at home after IRA attacks. The Prevention of Terrorism Act 1974 introduced week-long detention without a warrant and created a list of proscribed organisations. Home secretary Roy Jenkins admitted the powers were “draconian”, but the “temporary” law lasted 26 years.

Since then, legislation has tended to arrive after crises—and then stay. After 9/11, the Anti-Terrorism, Crime and Security Act 2001 allowed indefinite detention of foreign suspects. When that lapsed, “control orders” replaced it in the 2006 Prevention of Terrorism Act. In 2000, Parliament created a permanent framework: the Terrorism Act 2000 ended the tradition of temporary, annually renewed powers and set a broad legal definition.

What changed in that 2000 law and later updates? First, speech moved closer to the centre. A 2019 amendment said even “expressing an opinion or belief that is supportive of a proscribed organisation”, if done “recklessly” as to encouraging others, could be an offence. Lord David Anderson KC warned this could criminalise mild sympathy like saying a group’s “heart is in the right place”. The 2006 Terrorism Act also introduced “glorifying” terrorism as a potential crime; critics said it risked catching legitimate debate.

Second, the definition itself grew wider. The Terrorism Act 2000 frames terrorism to include “serious violence against a person” but also “serious damage to property” or “serious disruption of an electronic system”. That last point matters. The UN has tried to focus the term on harm to people. UK critics—from rights groups to the government’s own reviewers—argue that including property damage makes it too easy to label protest actions as “terrorism”.

Third, proscription expanded. The list once named very few groups; it now covers many Islamist and far-right organisations as well. Some researchers say adding neo-Nazi groups gave a “liberal veneer” to tough powers, which could then be extended to the left. In recent years ministers and police leaders floated new labels such as “eco-extremists” or “extreme protest groups”, often pointing to climate activists like Just Stop Oil. The Prevent programme has also drawn criticism for referrals involving non-violent environmental or pro-Palestine expression.

So what changed with Palestine Action? Supporters argue the group targets property—factories, offices, equipment—rather than people. Critics of the ban say the Home Office is collapsing the moral and legal line between “violence against the person” and criminal damage. UN experts have warned the UK against using terrorism powers to handle protest and dissent.

Where does this leave the UK? One possibility is a chilling effect on speech and protest: if “reckless” supportive words risk prosecution, who speaks openly? Another is legal uncertainty: if terrorism can include property damage and speech acts, where should courts draw the boundary? The arc from colonial emergency powers to today’s speech-based offences suggests a question worth studying carefully: how wide can the label “terrorism” stretch before it undermines the very liberties it claims to protect?