Official Home Office data indicates that 3,021 terror-related arrests were made in Great Britain in the year ending 31 March 2026. This figure represents almost half of the 6,539 total arrests for terror-related activity since the 9/11 attacks in 2001.
The rise in arrests coincides with the proscription of Palestine Action, which took effect on 5 July last year. This ban has reportedly led to thousands of arrests for allegedly supporting the direct action protest group, the first such group to be proscribed under the Terrorism Act.
The ban on Palestine Action has faced criticism from UN experts, NGOs, and former directors of public prosecutions and security services. A legal challenge against the proscription is ongoing, with the next hearing scheduled at the UK Supreme Court on 4 November.
Liberty, which intervened in the legal challenge, stated that the increase in arrests suggests the UK's counter-terror laws are not fit for purpose, arguing that the government's definition of terrorism is too broad. Defend Our Juries (DOJ) claims that over 3,600 arrests since 9/11 are related to supporting Palestine Action, with approximately 2,500 people charged under section 13 of the Terrorism Act and at least 50 under section 12.