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

Yvette Cooper is preparing a written statement to put 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”.

The BBC has contacted Palestine Action for comment.

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.”

The group claimed its activists had evaded security and had put the air-to-air refuelling tankers “out of service”.

However RAF engineers have been assessing the damage, with a defence source earlier telling the BBC that they did not expect the incident would affect operations.

Thames Valley Police earlier said it had received a report about people gaining access to the base and causing criminal damage.

“Inquiries are ongoing to locate and arrest those responsible,” the force said.

The incident sparked outrage among some MPs, with Reform UK leader Nigel Farage and shadow justice secretary Robert Jenrick calling for the group to be banned.

Since the start of the current war in Gaza, Palestine Action has engaged in activities that have predominantly targeted arms companies. In May, it claimed responsibility for the daubing of a US military plane in Ireland.

RAF Brize Norton serves as the hub for UK strategic air transport and refuelling, including flights to RAF Akrotiri in Cyprus. The air force has conducted reconnaissance flights over Gaza out of the Cyprus base.