Palestine Action demonstrators may never be able to visit the US or work in education if they take part in this weekend’s protest, the Met Police have warned.

The force have said those in attendance risk being arrested under the Terrorism Act.

It comes after three supporters of Palestine Action were the first to be charged under the Act, Scotland Yard has said.

The group was proscribed as a terror organisation last month after an alleged attack on aircraft at RAF Brize Norton.

Two women and a man, who were arrested at a demonstration on July 5 and later charged, are set to appear in court next month.

Deputy Assistant Commissioner Ade Adelekan has warned participating at the protest could have serious consequences for the future.

The Daily Telegraph reported he said: ‘I would urge those people to consider the seriousness of being arrested under the Terrorism Act and the very real long term implications from – from travel, to employment, to finances, that such an arrest is likely to have for their future.’ 

Being arrested for a terror offence – even if later cleared – could stop you from travelling to the US or working in education, lawyers have urged.

Membership of, or support for, Palestine Action is a criminal offence punishable by up to 14 years in prison, under the Terrorism Act 2000. 

At least 500 activists are set to swarm the police this Saturday and join a demonstration at Parliament Square, in which they will hold signs saying ‘I oppose genocide, I support Palestine Action‘.

It has fuelled fears of a ‘mass arrest’ event, with police and No 10 confirming this week that anyone who supported the newly proscribed terror group would be arrested.

But Tim Crosland, co-founder of Defender Our Juries, which is organising this weekend’s protest, said he was ‘proud’ of those who had signed up to show support for Palestine Action, calling them ‘the moral backbone of this country’.

He told Times Radio that arresting peaceful protesters was a waste of police time.

Prison bosses have initiated emergency measures for a possible influx of arrested demonstrators this weekend amid concerns that some jails are close to full.