More than 500 Palestine Action supporters are set to stage a protest in London with the intention of provoking mass arrests and overwhelming police.
Campaigners have planned for Left-wing activists and members of the Muslim community to deliberately flout terrorism laws by declaring their support for the banned group in Parliament Square on Saturday.
To do so would be an offence under the Terrorism Act 2000 and would be punishable by up to 14 years in prison.
In a warning to organisers, the Metropolitan Police charged three supporters of the group on Thursday, who became the first to face such charges.
More than 200 protesters have been arrested during marches by Defend Our Juries, who organise the gatherings, since the Palestine Action ban came into force last month.
