Wearing grey trousers and a shirt and tie, as though dressed for a day at the office, an elderly, bespectacled man sat down on the grass at Parliament Square. He, like hundreds of others, had come to Westminster to show support for an organisation that is now at the centre of an increasingly toxic political and legal row.

Crowds of people protesting the British government’s decision to ban the activist group Palestine Action gathered in central London on Saturday in a show of support.

Police say they arrested almost 900 protesters outside Parliament in London for defying a ban on the group Palestine Action, which the government has labeled a terrorist organization.