The latest move by the Russian foreign ministry is in retaliation for the expulsion of the same number of Russian diplomats in Britain in the past few days.
"But 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 worldwide rules-based system, on which all countries, all countries including Russian Federation, depend for their safety and security".
The Russian Foreign Ministry said it was giving the 23 British diplomats one week to leave the country.
Escalating a crisis in relations, Russian Federation said it was also shutting down the activities of the British Council, which fosters cultural links between the two countries, and Britain's consulate-general in St. Petersburg. They are now in critical condition in a local hospital.
Rising tensions with the West over the poisoning of former double agent Sergei Skripal in Britain, and new sanctions from Washington over alleged election meddling, strengthen the impression of a Russian Federation at loggerheads with the rest of the world.
UK-Russia relations have been fractious ever since the assassination of another former Russian spy, Alexander Litvinenko, in 2006.
Sobchak has posed as a defender of liberal values and denounced Putin's policies, but many observers believe the Kremlin has given its tacit blessing for her to join the contest hoping that she would add an element of competition to the otherwise lacklustre race.
The move comes a day before Russia's presidential elections, which President Vladimir Putin is expected to win. The leaders stressed that they share Britain's opinion on Russia's involvement in this incident, and they called Moscow for providing the information about Novichok agent (a series of nerve agents developed by the Soviet Union and Russiabetween 1971-1993, -ed.) to the OPCW (Organization for the Prohibition of Chemical Weapons). The British Embassy in Moscow told CNN it had been given a list of 23 specific individuals that were to be expelled from Russian Federation.
British police said there is no apparent link between the attack on Glushkov and the poisoning of the Skripals, but both have raised alarm in the West at a time when Russian Federation is increasingly assertive on the global stage and is facing investigations over alleged interference in the Donald Trump's 2016 election as USA president.
The British Council said it was profoundly disappointed by Russia's decision and remained committed to developing long-term people-to-people links with Russian Federation despite the closure.
Sergei Skripal, a 66-year-old former colonel in Russia's military intelligence service, and his 33-year-old daughter, Yulia Skripal, were found dead slumped on a bench in a British shopping district in Salisbury earlier this month. "It's impossible not to respond in this situation".
A Russian lawmaker is warning Britain against escalating the crisis over the poisoning of a former Russian spy. British police said Friday that he died from compression to the neck and opened a murder investigation.
Russian investigators said on Friday they had opened a criminal investigation into the attempted murder of Yulia Skripal and offered to cooperate with British authorities.
In January 2012 a former top aide to then British prime minister Tony Blair admitted that Britain had a spy plot involving a fake rock.