A former general who served in Afghanistan today warned Jeremy Corbyn cannot be trusted with the nation's security after the Labour leader said he would not use Trident.

Lord Richards, who served as Chief of the Defence Staff, joined Defence Secretary Sir Michael Fallon in a stinging attack on the Labour leader today.

The Labour leader is underfire after he used his first major TV interview of the election campaign to make clear he would never use the nuclear deterrent and could even scrap it.

Mr Corbyn's claims are in defiance of official Labour policy and the party has scrambled to insist its position is unchanged.

Jeremy Corbyn (pictured campaigning in Scotland today) is a security risk to Britain and he must not win the election, Sir Michael Fallon warned today

Mr Corbyn made no mention of national security at a rally with trade unionist supporters today (pictured) but instead stumped for his plans to reform the economy

A Labour source told MailOnline today 'there won't be any change on trident policy, whatever Jeremy Corbyn may or may not say'.

Mr Corbyn also told the BBC's Andrew Marr he would halt air strikes on ISIS and suggested he would not authorise a drone strike against the group's leader.

Writing in the Telegraph, former general Lord Richards said: 'Jeremy Corbyn, unlike many of his distinguished predecessors in the Labour Party from Clement Attlee through Denis Healey and beyond, has demonstrated why he should not be trusted with the ultimate responsibility of government – that of the nation's defence and security.'

Sir Michael told ITV's Good Morning Britain: 'I think 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.'

Former chief of the defence staff Lord Richards said Jeremy Corbyn could not be trusted with the nation's security (file)

Sir Michael said it was vital to be clear about being a nuclear power and warned the Government could not entirely rule out ordering a nuclear first strike.

He told the Today programme: '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.'

Asked about Sir Michael's comments on a pre-emptive strike, the Prime Minister's official spokesman said there was 'no reason to disagree with what the Defence Secretary said'.

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.

Sir Michael Fallon (pictured at the Bristol and Bath Science Park today) has revealed Theresa May would be prepared to launch a pre-emptive strike if necessary

The Defence Secretary (pictured on Friday announcing a new missile system) said Mr Corbyn was 'irresponsible' to campaign for power on a platform that undermines Britain's commitment to the nuclear deterrent

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

Sir Michael said Theresa May, pictured leaving Tory headquarters today, could be trusted to defend national security

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

Asked directly on ITV's Good Morning Britain programme whether he personally would kill the Isil leader, Mr Gwynne said: 'Yes. Yes.'

He continued: 'The Labour Party will never ever put the defence of the realm at the back of the queue.

'Jeremy will as prime minister put the defence of the real first and foremost. Any Labour leader, any Labour prime minister will do that.'

Sir Michael's comments signalled that the Tories intend to make Mr Corbyn's suitability for high office a key issue in the general election campaign.

But he was unable to stamp out questions over whether Theresa May will recommit to David Cameron's pledge not to put up to income tax, VAT or national insurance.

The Defence Secretary left the door open to tax rises, admitting the Tories do not want to commit to too many 'prescriptive' targets in its general election manifesto.

The Tory reluctance to tie their hands on tax is likely motivated by the party's commanding lead in every opinion poll over the past week

The Labour leader is underfire after he used his first major TV interview of the election campaign (pictured on Andrew Marr yesterday) to make clear he would never use Trident and could even scrap it

Tories appear to kill off their vow not to hike taxes as Michael Fallon warns the manifesto will not contain 'too many prescriptive' promises

Sir Michael Fallon moved the Tories closer to axing their pledge to hike taxes today with a warning the manifesto would not contain 'prescriptive' promises.

The intervention will further raise fears the Conservative Party will hike taxes if as expected they win the snap election.

In 2015 the party campaigned on a promise not to raise income tax, national insurance or VAT - branded a tax lock by David Cameron.

Theresa May has refused to repeat the promise since calling the election seven days ago, insisting only that the Conservatives are a party of low taxes.

The Defence Secretary's intervention will further raise fears the Conservative Party will hike taxes if as expected they win the snap election

Sir Michael told ITV's Good Morning Britain: 'I think what (Chancellor Philip Hammond) said is he doesn't want too many targets inside the manifesto that are too prescriptive, that don't allow you, as the situation develops over the lifetime of the Parliament, that don't allow you the flexibility.'

Asked if the Tories would rule out rises in income tax, VAT or national insurance, Sir Michael said: 'The manifesto will certainly make clear which side of this argument we're on — it's Labour governments that increase tax, it's Conservative governments that take the lower paid, in particular, out of tax.'