Palestine Action is to be proscribed as a terrorist organisation after its activists damaged two RAF planes at an air base.

The organisation will be added to the list of banned groups alongside Hamas, al-Qaeda and Islamic State after its activists broke into RAF Brize Norton and sprayed red paint into the engines of two Airbus Voyager aircraft.

The move means that it will be illegal to be a member of the group, to invite support for it or to wear clothing or carry flags or placards backing it. Anyone caught doing so will face up to 14 years in jail.

The Government will have to lay an order in Parliament with a vote by both Houses before the ban can take force.

It is expected that ministers will set out their plans in a written statement to Parliament on Monday.

Proscription means that Palestine Action’s assets and money can be seized. Sources said that its ability to operate openly in the UK will be “significantly degraded” because of the offences attached to membership and inviting support.

Hizb ut-Tahrir was the most recent organisation to be proscribed in January 2024 by James Cleverly, then then home secretary, after its members were accused of praising and celebrating Hamas’s terrorist attack on Israel on October 7.

Counter-terror police are leading an investigation into the incident at RAF Brize Norton.

Footage posted online by Palestine Action on Friday morning showed two people inside the air base in Oxfordshire.

The clip shows one person riding an electric scooter up to an Airbus Voyager air-to-air refuelling tanker and appearing to spray paint into its jet engine.

A spokesman for Counter Terror Policing South East said: “An incident at RAF Brize Norton in Oxfordshire is now being investigated by officers from Counter Terrorism Policing South East.

“In the early hours of today (20/6) offenders gained entry to the site and caused criminal damage to aircraft.

“Specialist counter terrorism officers are working closely with officers from Thames Valley Police and the Ministry of Defence Police.”