London police arrested 139 people outside the US Embassy on Saturday, 31 October 2026, during a protest in support of Palestine Action, a group proscribed in the UK. The Metropolitan Police said most of those detained were arrested on suspicion of expressing support for a proscribed organisation. This is an updated total for the same protest: an earlier police count on the day stood at 48, before arrests continued into the evening.

Officers began making arrests shortly after 12.30pm outside the embassy in Nine Elms, south London, where demonstrators held placards reading "I oppose genocide, I support Palestine Action". A dispersal order covering parts of London, including the embassy grounds, was in place from 8am to 11pm. The protest was organised by Defend Our Juries, which campaigns against the ban.

More than 4,000 arrests claimed since the ban

Defend Our Juries says more than 4,000 people have now been arrested for defying the ban since it took effect in July 2025. That figure is the campaign group's count, not an official police total. A parallel demonstration outside the US Consulate in Edinburgh drew no reported arrests on Saturday, although Police Scotland said it was reviewing evidence.

Supreme Court hearing on 4 November

Palestine Action was proscribed under terrorism laws in 2025, making membership of, or support for, the group a criminal offence punishable by up to 14 years in prison. The High Court ruled earlier this year that the ban was disproportionate, but the Court of Appeal upheld it in June. The Supreme Court is due to hear an appeal against the proscription on 4 November, days after Saturday's arrests.