It comes as Moscow responds to recent diplomat expulsions by more than two dozen countries
One Irish diplomat is to be expelled from Russia, as the Russian government continues its tit-for-tat response to recent expulsions of its diplomats by western countries.
Earlier this week, more than two dozen countries expelled Russian diplomats in solidarity with the UK.
The international response came in the wake of the British government's claims that Moscow was responsible for the Salisbury nerve agent attack.
Russia has denied any involvement in the poisoning.
Ireland confirmed one Russian diplomat would be expelled, with Tánaiste and Foreign Affairs Minister Simon Coveney arguing that Ireland had an "obligation to act and to send a clear signal that what happened in Salisbury was unacceptable."
Ambassadors of countries involved in expulsions, including Ireland's Adrian McDaid, were today summoned to the Russian foreign ministry to learn of Moscow's response.
In a statement this afternoon, the Department of Foreign Affairs confirmed one Irish diplomat has been instructed to leave Russia.
A spokesperson for Minister Coveney said: “There is no justification for this expulsion. Our staff do not engage in activities which are incompatible with their diplomatic status.
"This decision to expel an Irish diplomat is regrettable.”
It was not revealed which diplomat would be asked to leave Russia.
Ambassadors from other countries who expelled diplomats have also been receiving details of the Russian response.
Yesterday Sergei Lavrov, the Russian foreign minister, said Russia will close down the US consulate in St Petersburg and expel 60 US diplomats in response to similar moves by the Trump administration.
Former Russian double agent Sergei Skripal and his daughter Yulia were targeted in the Salisbury attack.
While Mr Skripal remains in a critical condition, his daughter's condition is now said to be 'improving rapidly'.