The home secretary will move to proscribe the Palestine Action group in the coming weeks, effectively branding them as a terrorist organisation, the BBC understands.

Yvette Cooper is preparing a written statement before Parliament on Monday – which if passed will make becoming a member of the group illegal.

The decision comes as a security review begins at military bases across the UK, after pro-Palestinian activists broke into RAF Brize Norton in Oxfordshire and sprayed two military planes with red paint.

Prime Minister Sir Keir Starmer condemned the action as “disgraceful,” describing it as an “act of vandalism”.

South East counter terrorism police confirmed its specialist officers were investigating the incident alongside Thames Valley Police and the Ministry of Defence (MoD).

Counter-terrorism police added the incident happened in the early hours of Friday and that enquiries were “ongoing to establish the exact circumstances”.

Footage posted online by Palestine Action on Friday showed two people inside the Oxfordshire airbase in darkness, with one riding on a scooter up to an Airbus Voyager and spraying paint into its jet engine.

After sharing the footage, a Palestine Action spokesperson said: “Despite publicly condemning the Israeli government, Britain continues to send military cargo, fly spy planes over Gaza and refuel US and Israeli fighter jets.”