Vladimir Putin's ambassador to the UK has been summoned by the Foreign Office in a tit-for-tat move.
The Foreign, Commonwealth and Development Office has confirmed that it has revoked a Russian diplomat's accredition.
Last month, Moscow made a similar "unjustified" decision to Britain's ambassador to Russia when the Kremlin expelled a British diplomat from the country.
The FCDO confirmed it took "reciprocal action" for Moscow's behaviour in March.
The British Government went on to issue a stern warning, telling Russian authorities any further action from their side would be treated as an escalation.
They confirmed that such escalation would be met with a "firm and proportionate" response.
A Government spokesman said: "We strongly condemn Russia’s unjustified decision last month to expel another British diplomat and the malicious public smear campaign that followed.
"This behaviour is wholly unacceptable, and we will not tolerate harassment or intimidation of our diplomatic staff.
Russian diplomat Andrey Kelin
|GETTY
"We have therefore summoned the Russian ambassador to announce we are taking reciprocal action, revoking the accreditation of a Russian diplomat.
"Russia’s repeated unprovoked and unjustified actions are designed to disrupt our diplomatic work and form part of a wider campaign of aggressive behaviour towards the UK.
"Any further action by Russia will be treated as an escalation and met with a firm and proportionate response."
Just a few weeks ago, a British diplomat, who remains unnamed, was thrown out of Russia after they were accused of espionage.
LATEST ON VLADIMIR PUTIN:
The Foreign Office declared it had taken 'reciprocal action'
|GETTY
The expulsion marks the second UK ambassador to be removed from Russia after the first was expelled for similar reasoning earlier this year.
The Kremlin's security and counterintelligence agency claimed to have uncovered an "undeclared intelligence presence".
They said the suspect was "carrying out intelligence and subversive activities that threaten the security of the Russian Federation", Russian media reported.
British officials subsequently accused Moscow of conducting an "aggressive and co-ordinated campaign of harassment".
They branded the claims as "malicious" and "baseless".
On March 30, the British charge d’affaires, the diplomat who oversees the embassy while the ambassador is absent, was summoned before the foreign ministry.
A diplomat subsequently ordered to leave within two weeks.
Back in January, the ministry vowed to not "tolerate the activities of undeclared British intelligence officers in Russia".