The British government will defend its decision to ban Palestine Action at the UK Supreme Court, in a landmark case that continues to test the boundaries of British counterterror legislation, freedom of speech and the right to protest.

The appeal, which begins on Wednesday and is expected to last two days, comes amid mounting civil unrest and police crackdowns across Britain in relation to the ban on Palestine Action.

A portion of the proceedings will be heard in secret because of the national security nature of the evidence.

Over the weekend, police arrested hundreds of demonstrators outside the US embassy in London and in Edinburgh for holding placards that read “I oppose genocide, I support Palestine Action”.