JEREMY Corbyn would put Britain's security at risk if he won power, Sir Michael Fallon, the Defence Secretary, has said as he denounced the Labour leader’s “irresponsible” comments on defence.

The Scot attacked Mr Corbyn, who is in Scotland today on a campaign visit, for calling into question Labour's commitment to the Trident nuclear deterrent and for suggesting he would be reluctant to authorise a drone strike on the leader of the Islamic State terror group, and could suspend RAF attacks against the extremists in Syria and Iraq.

He said such "irresponsible" comments showed the Labour leader was presiding over "very dangerous chaos" that would put the nation's security at risk.

“You saw Jeremy Corbyn yesterday questioning strikes against terrorists, refusing to back the nuclear deterrent, he's been querying our Nato deployment and he seems to have fallen out with his own party over the nuclear deterrent. That's chaos, but it's very dangerous chaos that would put the security of our country at risk," Sir Michael told ITV’s Good Morning Britain.

Sir Michael made clear a Tory Government could not rule out ordering a nuclear first strike. He explained: "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."

Labour has underlined its commitment to Trident renewal since Mr Corbyn used a Sunday broadcast interview to say he would order an immediate strategic defence review looking at "all aspects" of defence policy if he was prime minister after June 8.

Echoing a statement from a party spokesman issued after the interview, Andrew Gwynne, the Labour campaign chairman, said renewal of Trident would be in the party's manifesto.

"Yes, it's Labour Party policy. We are committed to renewing the Trident system," he told BBC Radio 4's Today programme.

In September 2015 shortly after he became leader, Mr Corbyn, asked if he would ever push the nuclear button, replied: “No. 187 countries don’t feel the need to have a nuclear weapon to protect their security, why should those five need it themselves? We are not in the era of the Cold War any more; it finished a long time ago.”