Nearly half of all terrorism-related arrests in Great Britain since the 2001 September 11 attacks have occurred in the past year, according to official figures released by the Home Office. Between 2001 and March 31, 2026, there have been 6,539 arrests linked to terrorism, with 3,061 of those taking place in the 12 months ending in March.
This surge in arrests coincides with the government’s decision to proscribe Palestine Action, a direct action protest group, on July 5, 2025. Palestine Action is the first group to be banned under the Terrorism Act, and its proscription has been followed by thousands of arrests of individuals allegedly supporting the group. The ban has prompted widespread criticism from United Nations experts, non-governmental organisations, a former director of public prosecutions, and a former head of the security services. The legality of the ban is currently being contested in court, with a hearing scheduled at the Supreme Court for November 4.
Advocates for civil liberties argue that the recent increase in arrests highlights flaws in the UK's counter-terrorism framework. Ruth Ehrlich, director of external relations at Liberty—an organisation involved in the legal challenge—described the rise as “staggering” and attributed it to an overly broad definition of terrorism. She warned that when the legal boundaries of terrorism are unclear, public trust deteriorates, undermining the effectiveness of counter-terror laws. Ehrlich called for a revision of the terrorism definition to balance public safety with the protection of individual rights and to prevent governmental overreach.
The heightened enforcement followed a wave of civil disobedience, particularly demonstrations organised by the group Defend Our Juries (DOJ), whose members have been arrested for displaying placards bearing messages such as “I oppose genocide, I support Palestine Action.” Terrorism-related arrests increased by 1,434% compared to the previous year, with women and girls arrested rising by 3,761% and arrests of individuals aged 30 and over increasing by 2,306%.
Legal professionals have also commented on the nature of the arrests. Raj Chada, head of criminal defence at Hodge Jones and Allen law firm, stated that the most common profile of those arrested under terrorism laws has shifted to include older individuals participating in silent vigils.
According to DOJ, more than 3,600 arrests have been linked to support for Palestine Action, which they claim targets UK organisations alleged to be complicit in human rights abuses against Palestinians. This figure would represent over half of all terrorism-related arrests since 9/11. Approximately 2,500 people have been charged under section 13 of the Terrorism Act, which prohibits showing support for proscribed groups and carries a maximum sentence of six months in prison. Meanwhile, over 50 individuals face charges under section 12, which involves inviting support for a banned organisation. Those cases require jury trials and can lead to sentences of up to 14 years.
Representatives from DOJ argue that the police and government are using terrorism legislation to suppress peaceful protest and dissent rather than to protect public safety. A spokesperson stated that thousands of peaceful activists have been arrested simply for expressing opposition to genocide and supporting direct action against it since the ban took effect.
In response, a Home Office spokesperson maintained that showing support for proscribed organisations is illegal and that decisions to arrest are operational police matters made based on the facts and circumstances of each case. The government has not commented further on the criticism surrounding the scope of counter-terrorism measures.