Moscow threatened to take further action against embassy employees if London responds to the expulsion by targeting its diplomatic representatives in the U.K.
Russia ordered a British diplomat to leave the country over allegations of espionage on Monday.
The Federal Security Service (FSB) claimed it had uncovered an “undeclared British intelligence presence” operating within the U.K. embassy in Moscow. It accused the diplomat of providing false information to obtain entry into Russia and engage in intelligence-gathering activities.
According to the FSB, the diplomat attempted to obtain sensitive information about Russia’s economy during informal meetings, actions it said posed a threat to national security. The agency said it had identified “signs of intelligence and subversive activities” linked to the official, who had been working as a second secretary at the embassy in Moscow and has been asked to leave the country within two weeks.
In a statement, Russia’s foreign ministry warned it “will not tolerate the activities of undeclared British intelligence officers on Russian territory,” adding that it would “respond accordingly” if London took action against Russian diplomats.
Britain’s Foreign Office told POLITICO Moscow’s accusations are “completely unacceptable” and said it would not tolerate acts of intimidation targeting embassy employees and their families in Russia. London additionally accused Moscow of waging an “increasingly aggressive and coordinated campaign of harassment” against diplomats through “malicious and completely baseless” claims.
The latest expulsion follows a similar incident in January, when Russia made comparable espionage allegations against a British diplomat — claims the U.K.’s Foreign Office also dismissed as unfounded.