Police are planning to arrest anyone demonstrating in support of Palestine Action this weekend.
The group has been banned under terrorism laws and this weekend a large event protesting against its proscription has been organised by the group Defend Our Juries.
A source with knowledge of the police’s early planning for this Saturday’s event said: “If they think that by turning up with significant numbers that we can’t arrest them for breaking terrorism laws, they need to think again.
“They will be arrested. However we have to do it, they will be arrested for breaking terrorism laws.”
The Met is aware of the planned protest this Saturday and is sceptical of claims that thousands could turn up. The force believes that a total in the low hundreds is more likely. Anyone arrested risks a terrorism conviction.
At other events that led to mass arrests, the Met has arrested people, confirmed their identities and home addresses and then quickly released them on bail so they can be dealt with later.
That tactic was used for an anti-immigration protest in Whitehall last summer and for past Extinction Rebellion protests where scores of people were arrested.
Police will be stretched at the weekend as a large, separate pro-Palestinian march is also scheduled for Saturday and anti-immigration protests are also expected.
The Met’s plans will evolve throughout the week, and police chiefs will consider whether the force – Britain’s largest – may need to call on mutual aid from others to manage.
The Met faces dangers from both sides of the debate. Supporters of Palestine Action may accuse police of being heavy-handed if they make mass arrests, while those on the right may accuse the Met of going soft if people openly break terrorism laws and are not arrested.
A spokesperson for Defend Our Juries denied any plot to overwhelm the police and the courts system, as was reported in the Telegraph on Monday. They said: “It’s great the Telegraph is helping us to spread the word but there are serious inaccuracies in their story.
“First, it’s not a ‘Palestine Action’ campaign. Defend Our Juries is organising the campaign, as they must know since they’ve seen the briefing document. Given that PA is currently a proscribed organisation that’s an important distinction.
“Secondly it’s not a ‘plot’. Plot implies something underhand and secretive. This is an open and transparent campaign against an unjust law, which violates basic democratic freedoms. All materials, including the action briefing document, are available on the website.
“Third, we’re not planning to overwhelm the system. The police have a choice whether to arrest people or not. If the police show respect for the law and basic democratic rights, they will leave peaceful protesters be. It’s only if they choose to arrest peaceful protesters that they’ve got a problem, which is on them, not us.”