The Federation Council, the upper chamber of Russia's parliament, on Friday barred British diplomats, including the ambassador, from entering its building.
Speaking at a livestreamed session of the upper chamber's rules committee on Friday, senator Grigory Karasin said that the ban was in response to a British decision to exclude Russian diplomats from its parliament.
Karasin said: "The decision is quite simple, although unpleasant, but it is required for this situation. Our country must be firm in upholding its own positions and in upholding its honour."
Britain's Guardian newspaper on June 20 reported that Russian diplomats were banned from visiting the country's parliament following Russia's deployment of tens of thousands of troops to Ukraine, citing a document signed by the speakers of the Houses of Commons and Lords.
(Reporting by Reuters; Editing by Mark Heinrich and Barbara Lewis)