British police arrested more than 50 people outside the annual Labour Party conference in Liverpool, a port city in northwest England, on Sunday after demonstrators displayed material in support of Palestine Action, a group proscribed as a terrorist organisation by the UK government in July 2025. Officers from Merseyside Police confirmed the arrests in a statement, saying those taken into custody had been warned that holding banners expressing support for the group constituted a violation of the Terrorism Act before being led away. Around 250 protesters had gathered outside the conference centre, many carrying signs reading "I oppose genocide. I support Palestine Action." Among those arrested were Robert Del Naja, vocalist of the British band Massive Attack, and Margaret Owen, a 94-year-old human rights lawyer.

Palestine Action rose to prominence through acts of civil disobedience targeting military and defence industry sites, including breaking into an air force base and daubing military aircraft with red paint. The Labour government designated it a terrorist organisation under the Terrorism Act, a decision upheld by London's Court of Appeal in June, which acknowledged the ban was "highly controversial" but concluded that the group "openly promotes unlawful violence amounting to terrorism." The UK Supreme Court is now set to hear the case. Since the proscription, a broad civil disobedience movement has grown around it, with more than 3,600 people reportedly arrested for publicly expressing support.

The protests coincided with the first day of the conference under Prime Minister Andy Burnham, and demonstrators said they wanted to place the proscription at the top of his agenda. Separately, activists confronted Foreign Secretary Ed Miliband at a restaurant in Liverpool, demanding he lift the ban and formally recognise what they described as Israel's genocide in Gaza. Miliband reportedly declined to comment and the activists left without an incident.

Kerry Moscogiuri, chief executive of Amnesty International UK, condemned the arrests in strong terms, calling them "a truly shameful attack on freedom of speech" and noting that those detained included grandparents and teenagers. She called on Burnham to reform protest laws "so that communities are protected in coming together and demonstrating on the issues they care about." One protester told reporters that being arrested was "nothing in comparison to what the people in Gaza are going through," while another emphasised the diverse backgrounds of those present, including priests and healthcare workers. The episode has intensified a debate in Britain over where the boundary lies between counterterrorism law and the fundamental right to protest.