Jeremy Corbyn heckled by debate audience for refusing to say if he would fire nuclear weapons

'Would you allow North Korea or some idiot in Iran to bomb us and then say ‘ooh, we’d better start talking’? You would be too late'

Jeremy Corbyn was heckled by a live TV audience as he repeatedly refused to say if he would fire Britain’s Trident missiles if the country was under “imminent threat from nuclear weapons”.

The Labour leader had his most uncomfortable moment of the election campaign after he claimed he would deal with the threat “earlier by negotiation and talks”.

Mr Corbyn went on to duck questions about whether he would “retaliate” if Britain had suffered a nuclear attack – replying: “If we did use it, millions would die.”

One questioner said: “I find it incredibly concerning that you wouldn’t ever commit to doing that. It’s our safety that you have to look out for first and foremost.”

A second said: “Would you allow North Korea or some idiot in Iran to bomb us and then say ‘ooh, we’d better start talking’? You would be too late.”

Mr Corbyn was accused by BBC presenter David Dimbleby of “dodging the question” and of thinking about an “ideal” situation” – rather than of the stark “reality” of nuclear threat.

Ruling out “first use” of Trident, the Labour leader said: “I would do everything I can to ensure that any threat is actually dealt with earlier on by negotiations and talks

“The idea of anyone ever using a nuclear weapon anywhere in the world is utterly appalling and terrible.”

Asked if he never fire Trident “under any circumstances”, Mr Corbyn replied: “The most effective use of it is not to use it, because it’s there.”

Later, he said: “If we did use it, millions are going to die – you have to think this thing through. I will decide it on the circumstances of it at the time.”

Mr Corbyn did receive some support and there was loud applause when one woman said: “I don’t understand why everyone in this room seems so keen on killing millions of people?”

However, many in the audience appeared hostile – apparently making real the fear of many Labour MPs that his stance on nuclear weapons would eventually undermine his successful campaign.

Boris Johnson, the Foreign Secretary, condemned his comments, saying: “I thought it was really spine-chilling to hear Jeremy Corbyn announce that all Labour's support for our nuclear deterrent, all Labour's support for our Armed Forces was completely meaningless because, when it came to the business of defending this country, he wouldn't do it.”

Mr Corbyn also faced tough questions over his past comments about the IRA, one person asking: “Why have you never regarded the IRA as terrorists?”

When another audience member pointed out the IRA “did kill a lot of people didn't they”, he replied: “All deaths are wrong.”

Mr Corbyn also hit out at Donald Trump over his decision to pull out of the Paris climate change deal - and Mrs May's decision not to sign a letter with other EU leaders condemning the move.

“I utterly deplore Donald Trump's decision,” he said. “I would sign a letter with any other leader that would deplore that, straightaway.”

The Labour leader insisted he would not strike a deal with SNP leader Nicola Sturgeon and was working for a majority Labour government.

“We are fighting this election to win and we are mounting a fantastic campaign in order to get that message across of how different our society and our politics could be,” he said – adding “no deals”.

Asked if he wanted to reduce immigration, Mr Corbyn said there would be “managed migration” from within the EU after Brexit, as there is currently from outside.