Hundreds of activists descended on Parliament Square in London, deliberately provoking police arrests by displaying signs supporting the recently banned group Palestine Action. Over 360 protesters were detained for supporting the proscribed organisation, with additional arrests made for assaulting officers and breaching bail conditions. The large-scale demonstration required more than 850 police officers, including reinforcements from other regions, and led to violent scuffles and heated exchanges between demonstrators and law enforcement.

Officials estimate the day's policing and legal costs could reach £3 million, adding to the substantial sums already spent on similar protests since last year. Temporary processing centres were set up to handle the influx of detainees, some of whom returned to the protest after being bailed. The event has sparked debate over the financial and social impact of such mass actions, with authorities emphasizing the seriousness of supporting banned organisations.