The British government has expelled a Russian diplomat in response to Moscow’s removal of a British official last year, escalating tensions between the two nations.

On Thursday, the U.K. revoked the accreditation of the Russian diplomat, marking the latest tit-for-tat move in the ongoing diplomatic row. Russian Ambassador Andrey Kelin was summoned to meet a senior British official, according to a spokesperson for the Foreign, Commonwealth and Development Office (FCDO). The spokesperson described the decision as a direct response to Russia’s “unprovoked and baseless” expulsion of a British diplomat in 2023.

“The U.K. will not tolerate intimidation of its personnel, and we are taking reciprocal action,” the FCDO spokesperson stated. “Any further measures taken by Russia will be regarded as an escalation and met with an appropriate response.”

The dispute stems from Russia’s decision in November to expel a British diplomat, accusing them of espionage. The FSB, Russia’s domestic intelligence agency, claimed the diplomat had engaged in “reconnaissance and subversive activities” that posed a threat to national security. Russian authorities also alleged the individual had provided false information when applying for entry into the country, violating local laws.

At the time, Downing Street dismissed the accusations as “baseless.”

The diplomatic spat adds to growing tensions between London and Moscow. Last month, U.K. Defence Secretary John Healey confirmed that a Russian spy ship had entered British waters on two occasions, in November and January. Photo by Foreign and Commonwealth Office, Wikimedia commons.