State news agencies reported the country’s FSB security service said the diplomat – whose photo was shown on TV bulletins – had provided false information on his documents and carried out espionage and sabotage activities.
It added that the diplomat was a replacement for one of six UK diplomats expelled in August, also on espionage charges.
It comes amid worsening relations between the UK and Russia since the latter’s full-scale invasion of Ukraine in 2022.
Last week it emerged the UK lifted restrictions on Ukraine using British-supplied Storm Shadow missiles on targets inside Russia for the first time.
Expulsions of diplomats have become increasingly common since the war began.
Earlier this year, British diplomat Capt Adrian Coghill was given a week to leave Russia, days after the Russian defence attaché was expelled from London for alleged espionage as an “undeclared military intelligence officer”.
