Twenty three British diplomats have been declared personae non gratae and will be expelled within a week, Russia's Foreign Ministry said in a statement on Saturday, TASS reports. It also said it is ordering the closure in Russian Federation of the British Council, a government-backed organization for cultural and scientific cooperation, and is ending an agreement to reopen the British consulate in St. Petersburg.
The Russian ambassador to the United Kingdom responded by saying they "consider this a provocation", and earlier today, Russia ordered that 23 United Kingdom diplomats be expelled.
The Russian ministry also warned Britain that it "retains the right to take other answering measures" in response to any "further unfriendly actions".
This week, May expelled 23 Russian diplomats and severed high-level contacts over the poisoning of ex-spy Sergei Skripal and his daughter Yulia.
With Sergei Skripal fighting for his life in hospital after a nerve agent attack, Alexander Yakovenko says the British investigation has been "untransparent and secret".
Russian court officials at the time said he'd received at least $100,000 for his work for MI6, the British intelligence service.
"There is a certain British protocol in cases when the ambassador is summoned to the Foreign Ministry".
Two days ahead presidential elections in Russia, the Russian Investigative Committee has opened a case in the poisoning of Yulia Skripal.
Britain's foreign ministry said it had anticipated Russia's response and the National Security Council would meet early next week to consider next steps.
Britain's foreign minister Boris Johnson said Friday it was "overwhelmingly likely" President Vladimir Putin directly ordered the attack.
Russia, which denies any involvement in the incident, condemned May's decision as unacceptable and vowed a swift response.
Top EU diplomats were expected to discuss next steps at a meeting Monday, with some calling for a boycott of the upcoming World Cup in Russian Federation.
When asked if the Prime Minister was a liar, Yakovenko told Channel 4: "Definitely we would like to see the statements of the Prime Minister supported by facts".
Russian news agencies cited politicians in Russia's upper house of parliament as welcoming the move to close the British Council, alleging it had been used as a cover by British spies. Police said Glushkov died as a result of a "compression of the neck", suggesting he may have been strangled.
"Russia has never received any information from London through any channel".