The understatement by Tory frontbencher Baroness Goldie of such a catastrophic scenario, which she said she hoped could be avoided, sparked muted wry laughter among peers at Westminster.
Lady Goldie made her comments as she was pressed over a deal struck between the UK and Ukraine which will see warships and missiles sold to the country amid rising tensions with Russia.
Speaking in the House of Lords, former Navy chief Lord West of Spithead said: “The greatest risk to survival of mankind isn’t global warming, it’s an accidental thermo-nuclear war.”
He added: “One has to look at the dreadful behaviour of Putin, not just around the Ukraine but in a number of other ways and his very loose talk about his de-escalatory policy of using a nuclear weapon should he be losing a conventional war, to see what the real risks are.”
Arguing the situation with Ukraine had been “dealt with badly”, Lord West said: “We need to get back urgently round the table or there will be a mistake and goodness me that will be it.”
Lady Goldie said: “That would be a very alarming prognosis and a very unwelcome outcome, which I hope, obviously, can be avoided.”
She added: “He is aware of the programme of engagement which has continued over a number of years with Ukraine.”
As well as Nato, Lady Goldie said: “Ukraine enjoys a strong bilateral relationship with the United Kingdom and that is a relationship we value, it’s a relationship we nurture and as recent events have indicated it’s a relationship which we support by deeds in addition to words.”
Tory former MEP Lord Balfe, who raised the issue in the upper chamber, said: “In eastern Europe we seem to be drifting towards a war, which we will inevitably lose since we are outnumbered by about four to one.”
He stressed the need for a “comprehensive conference” to deal with the current fragile stand-off.
Lady Goldie said: “No one is disputing there is not a serious situation within Ukraine and on the Crimean peninsula, but that is precisely why over the last 20 years and very particularly within the last six years, the UK along with allies and partners has been supporting Ukraine.”
Highlighting the recent treaty with Ukraine, under which the country’s government can access financing for contracts with UK suppliers to help beef up its naval capabilities, she said: “That is all about supporting this country, helping it to build its military capabilities.”