Backers of Palestine Action have staged a series of protests since early July, when Parliament banned the group as a terrorist organisation.

British police said they arrested 365 people in central London on Saturday as supporters of a recently banned pro-Palestinian group intentionally flouted the law as part of their effort to force the government to reconsider the ban.

Parliament in early July passed a law banning Palestine Action and making it a crime to publicly support the organisation. That came after activists broke into a Royal Air Force base and vandalised two tanker planes to protest against Britain’s support for Israel’s offensive against Hamas in the Gaza Strip.

Backers of the group, who have held a series of protests around the UK over the past month, argue that the law illegally restricts freedom of expression.

More than 500 protesters filled the square outside the Houses of Parliament on Saturday, many daring police to arrest them by displaying signs reading “I oppose genocide. I support Palestine Action”. That was enough for police to step in.