Russian Federation is to expel 23 British diplomats amid tensions over the nerve agent attack on a former spy and his daughter in the UK.
Photo The British ambassador to Russia, Laurie Bristow, leaving the Foreign Ministry in Moscow on Saturday.
The British Council has also fallen victim to the escalating tensions, with Moscow on Saturday withdrawing its permission for the cultural institute to open a location in St Petersburg.
British Prime Minister Theresa May was briefed by police chiefs at the scene of the attack, saying the diplomatic expulsions in Moscow change nothing.
Skripal, a former colonel in the GRU who betrayed dozens of Russian agents to British intelligence, and his daughter have been critically ill since March 4, when they were found unconscious on a bench.
A Cold War-era nerve agent of a group called Novichok was used, according to British Prime Minister Theresa May.
Britain's foreign secretary accused Russian President Vladimir Putin of personally ordering the poisoning.
Having heard news, British Ministry of Foreign Affairs has said that it "expected such a response" from Russian Federation and announced that London will study "new measures" next week.
"The British side has been warned that if unfriendly steps are still taken in relation to Russia, Russian side reserves right to take or response measures", concludes Russian chancellery.
"We will always do what is necessary to defend ourselves, our allies and our values against an attack of this sort, which is an attack not only on the United Kingdom, but upon the global rules-based system on which all countries, including Russian Federation, depend for their safety and security", Bristow told reporters after being informed of the expulsions.
Britain's Foreign Office said in a statement on Saturday that the country's National Security Council would meet early next week to consider its next steps.More news: Russia Expels 23 British Diplomats In Ex-Spy Poisoning Standoff
The response comes amid a deterioration of London-Moscow relations over the consequent British punitive measures against Russia and the former Russian spy attack row.
Experts say Russian Federation is the only-known maker of Novichok.
On March 15 Britain, France, Germany and the U.S. say in a rare joint declaration that "there is no plausible alternative explanation" to Russian involvement and call on Moscow to provide "full and complete disclosure" of the Soviet-era chemical programme that developed Novichok.
Russian Federation has complained that Britain has failed to provide any evidence of its involvement in the Salisbury attack and has said it is shocked and bemused by the allegations.
"This crisis has arisen as a result of an appalling attack in the United Kingdom, the attempted murder of two people, using a chemical weapon developed in Russia and not declared by Russia at the Organization for the Prohibition of Chemical Weapons, as Russia was and is obliged to do under the Chemical Weapons Convention", he added. However German Chancellor Angela Merkel says that the European Union will not in the first instance discuss a boycott of the World Cup.
"It is possible that (Britain) will continue to respond; we are ready for this". They remain in critical condition.
British researchers claim that y were poisoned with a Russian-made nerve agent, so Moscow - which rejects all accusations - demands that London provide a sample of that material.
Meanwhile new tensions have surfaced over the death this week of a London-based Russian businessman, Nikolai Glushkov.
A murder investigation was launched after a pathologist's report gave the cause of the Russian exile's death as "compression to the neck".
The British embassy in Russian Federation is pictured on March 15, 2018.