A Russian MP has warned that Britain would be "literally erased from the face of the earth" in a nuclear war.
Defence Secretary Sir Michael Fallon said this week that "in the most extreme circumstances, we have made it very clear that you can't rule out the use of nuclear weapons as a first strike", in response to Labour rifts over keeping the Trident deterrent.
But Franz Klintsevich, a retired colonel, is quoted in Russian state media as saying Britain, "not having the biggest territory", would "literally be erased from the face of the earth" were it to launch a preemptive strike. He said:
"Against whom is Great Britain going to preemptively use nuclear weapons?"
Russian news agency TASS published another translation of the comments, which read that Britain would be "razed to the ground" in a retaliatory strike.
Mr Klintsevich, deputy chairman of the upper house of the Russian parliament's defence and security committee, called Sir Michael's comments "disgusting" and said they deserved "a tough response".
"In the best case this statement should be taken as an element of psychological war — which looks particularly disgusting in such a context."
He added that if Britain intended to use nuclear weapons against a non-nuclear state, "then probably English people desperately want to share the laurels of the USA who threw nuclear bombs at defenceless [Japanese cities] Hiroshima and Nagasaki [in 1945]."
"But those times have gone for good, as has the era of the greatness of the British Empire."
When asked in what circumstances Britain would launch a pre-emptive strike, Sir Michael said:
"They are better not specified or described, which would only give comfort to our enemies and make the deterrent less credible.
"The whole point about the deterrent is that you have got to leave uncertainty in the mind of anyone who might be thinking of using weapons against this country."
Labour leader Jeremy Corbyn, meanwhile, suggested that renewal might not be in the party's election manifesto - although he was later corrected by party colleagues.