The Russian Foreign Ministry on Saturday declared 23 diplomats of the British Embassy in Moscow persona non-grata, asking them to leave within a week.
Lauri Bristow, the U.K.'s ambassador to Russia, was summoned to the Foreign Ministry and handed a note listing countermeasures taken by Moscow in response to "provocative actions of the British side" over attempted murder of a former Russian spy and his daughter in the southern English city of Salisbury.
Former Russian spy Sergei Skripal, 66, and his daughter Yulia, 33, were admitted to a hospital on March 4 after being found unconscious in Salisbury.
British Prime Minister Theresa May alleged the duo was poisoned with a military grade nerved agent developed by Russia.
The Russian countermeasures include withdrawal of a consent to open the British Consulate General in St.Petersburg and termination of the British Council.
The Russian side reserves the right to take other retaliatory measures, the statement added.
The attack in Salisbury has drawn comparisons to the 2006 death of former KGB agent Alexander Litvinenko after he drank radioactive tea.
Skripal was granted refuge in the U.K. following a 2010 spy exchange between the U.S. and Russia. Before the exchange, he was serving 13 years in prison for leaking information to British intelligence.
