Russia has revoked the accreditation of six British diplomats in Moscow, accusing them of spying.

The FSB security service said the Russian foreign ministry has terminated the accreditation of six employees in the British Embassy in Moscow’s political department.

The move was in response to “numerous unfriendly steps” by London and after “signs of spying and sabotage” were found in the actions of the diplomats, the FSB said in a statement.

The news comes as Prime Minister Sir Keir Starmer meets US President Joe Biden in Washington and is expected to discuss Ukraine’s plea for restrictions to be lifted on using Western weaponry against Russian targets.

Concern about escalation has been one of the reasons why permission has not yet been given to Kyiv.

The US and UK this week announced further financial support for Ukraine, including a £600 million package from the UK and 717 million dollars (£550 million) from the US to meet immediate humanitarian, energy and stabilisation needs.

On Thursday, Russian President Vladimir Putin said that allowing long-range strikes would mean that Nato countries, the US, and European countries are “at war with Russia”.

Sir Keir responded to the remarks ahead of his meeting with Mr Biden, telling journalists that “Ukraine has the right to self-defence” but stressing that “we don’t seek any conflict with Russia”.

The diplomats will be expelled, Russian state TV reported, citing an FSB official.

Maria Zakharova, Russia’s Foreign Ministry spokesperson, said they were carrying out “subversive actions aimed at causing harm to our people”.

She said: “We fully agree with the assessments of the activities of the British so-called diplomats expressed by the Russian FSB.

“The British Embassy has gone far beyond the limits outlined by the Vienna Conventions.”

Russian state TV reported that the six diplomats met with independent media and rights groups that Russian authorities have declared to be “foreign agents”.

Earlier this year, the UK ordered Russia’s defence attache in London to leave, claiming he was a spy.

Moscow then expelled a Royal Naval officer based at the British Embassy in Moscow, giving him a week to leave the country.

The UK also revoked the diplomatic status of two Russian-owned properties in the UK that were believed to have been used for intelligence purposes, and placed new restrictions on Russian diplomatic visas.