LONDON (Reuters) -Britain said on Monday it would use anti-terrorism laws to ban the campaign organisation Palestine Action, making it a criminal offence to belong to the group after its activists damaged two UK military planes in protest at London's support for Israel.

The proscription would put the pro-Palestinian group on a par with Hamas, al-Qaeda or ISIS under British law, making it illegal for anyone to promote it or be a member. Those who breached the ban could face up to 14 years in jail.

Palestine Action has regularly targeted British sites connected to Israeli defence firm Elbit Systems as well as other companies in Britain linked to Israel since the start of the conflict in Gaza in 2023.

In its latest and most high-profile action, two of its members entered a Royal Air Force base in central England on Friday, spraying paint into the engines of the Voyager transport aircraft and further damaging them with crowbars.

"The disgraceful attack on Brize Norton ... is the latest in a long history of unacceptable criminal damage committed by Palestine Action," Home Secretary (interior minister) Yvette Cooper said in a written statement to parliament.

"The UK’s defence enterprise is vital to the nation’s national security and this government will not tolerate those that put that security at risk."

She said the group's actions had become more aggressive and caused millions of pounds of damage.

Under British law, the Home Secretary can proscribe a group if it is believed it commits, encourages or "is otherwise concerned in terrorism". The banning order will be laid before parliament on June 30 and will come into effect if approved.

Palestine Action, which says Britain is an "active participant" in the conflict in Gaza because of military support it provides to Israel, called the ban "an unhinged reaction" which it would challenge, and accused Cooper of making a series of "categorically false claims".

"The real crime here is not red paint being sprayed on these war planes," it said in a statement.

Earlier on Monday, the group was forced to change the location of a planned protest after police banned it from staging a demonstration outside parliament, otherwise a popular location for protests in support of a range of causes.

(Reporting by Sarah Young, Sachin Ravikumar and Sam Tabahriti; editing by William James, Alexandra Hudson)