The UK accuses Kremlin of trying to install a pro-Russian leader in Ukraine.
Britain accused the Kremlin of attempting to install a pro-Russian leader in Ukraine, and said Russian intelligence officers had been in contact with a number of former Ukrainian politicians as part of plans for an invasion.
The British foreign ministry did not provide any evidence to back up its accusations, which came at a time of high tensions between Russia and the West over Russia's mass troops near its border with Ukraine. Moscow has insisted it has no plans to invade.
The British ministry said it had been told that the Russian government was considering former Ukrainian lawmaker Yevhen Murayev as a potential candidate to lead a pro-Russian leadership.
The information released today shines light on Russian activity designed to subvert Ukraine, and is an insight into Kremlin thinking, British Foreign Secretary Liz Truss said in a statement.
Russia must de-escalate, end its campaigns of aggression and disinformation, and pursue a path of diplomacy. A Russian military incursion into Ukraine would be a huge strategic mistake with severe costs, as the UK and our partners have said repeatedly. The British statement was released in the early hours of Sunday, Moscow and Kyiv time, and there was no immediate statement from the Kremlin or Murayev.
A foreign ministry source said that it was not usual practice to share intelligence matters, and details had been declassified after careful consideration to deter Russian aggression.
British claims come a day after top US and Russian diplomats failed to make a major breakthrough in talks to resolve the crisis over Ukraine, although they agreed to keep talking.
Russia has made security demands on the United States including a halt to NATO's eastward expansion and a pledge that Ukraine will never be allowed to join the Western military alliance.
Murayev, 45, is a pro-Russian politician who opposes Ukraine's integration with the West. According to a December 2021 poll conducted by the Razumkov s Centre think tank, he was ranked seventh among candidates for the 2024 presidential election with 6.3 per cent support.
Britain, which supplied 2,000 missiles and a team of military trainers to Ukraine this week, said Russian intelligence services were linked to numerous former Ukrainian politicians, including senior figures with links to ex-President Viktor Yanukovich.
Yanukovich fled to Russia in 2014 after three months of protests against his rule and was sentenced in absentia to 13 years in jail in 2019 on treason charges.
Some of these have contact with Russian intelligence officers currently involved in the planning for an attack on Ukraine, according to the British foreign office statement.
The British leader plans to ramp up pressure on Russia this week by calling for European counterparts to come together with the United States to fight Russian aggression, according to Boris Johnson's Downing Street office.
Earlier, RIA news agency reported that British foreign minister Truss would visit Moscow in February to meet Russian defence minister Sergei Lavrov, while Russian defence minister Sergei Shoigu and British counterpart Ben Wallace also agreed to hold talks.