"Disinformation circulated by @FCDOGovUK is yet another indication that it is the @NATO Members led by the Anglo-Saxon nations who are escalating tensions around #Ukraine," the ministry said in a tweet.
"We urge the Foreign Office to stop spreading nonsense."
Britain on Saturday alleged that it had information that Moscow was "looking to install a pro-Russian leader in Kyiv" as fears grown of an invasion of Ukraine.
"We have information that indicates the Russian Government is looking to install a pro-Russian leader in Kyiv as it considers whether to invade and occupy Ukraine. The former Ukrainian MP Yevgen Murayev is being considered as a potential candidate," the Foreign Office said in a press release.