Jeremy Corbyn is a threat to our national security, says George Osborne

The Chancellor warned that the 'unholy alliance' of Corbyn and the SNP over nuclear deterrents could threaten the UK's 'freedom and safety'

The task of checking registrations may be left to the unions, several of whom back Jeremy Corbyn (Getty)

Britain's national security will be at greater risk if Jeremy Corbyn becomes leader of the Labour party, George Osborne has said.

The Chancellor said “an unholy alliance of Labour's left-wing insurgents and the Scottish nationalists” would undermine the future of the UK’s nuclear deterrent.

Both Jeremy Corbyn and the SNP oppose the renewal of Trident which the current Conservative government and previous Labour leaders have supported.

Earlier this month, the Labour leadership contender called for Britain's nuclear disarmament at a Campaign for Nuclear Disarmament (CND) event to mark the 70th anniversary of the bombing of Hiroshima.

Writing in the Sun in an article linked to the announcement of a £500m grant for the ROyal Navy's submarine base at Faslane, Mr Osborne rejected the idea that the Conservatives were delighted at Corbyn’s emergence as the favourite to win the leadership saying the contest should not be seen as a joke.

He wrote: “On the contrary, I think we should take it deadly seriously.

“For the new unilateralists of British politics are a threat to our future national security and to our economic security. We’re going to take on their dangerous arguments and defeat them.”

The Faslane grant will safeguard 6,700 jobs at the Scottish site and create thousands more, according to the Chancellor.

The cash will be spent on repairing ship lifts, sea walls and jetties at the base, which will be home to the nuclear Astute and Successor submarines, their crews and engineers until at least 2067. From 2020, Faslane will be the navy’s ‘Submarine Centre of Specialisation’ – all of the UK’s underwater capability will be located in Scotland.

Writing about Mr Corbyn’s likely victory in the Labour leadership Mr Osborne said it would shatter the decades long consensus in Westminster over the need for a nuclear deterrent.

The only breakdown in this agreement was during the 1980s when Labour was dominated by the left under the leadership of Michael Foot and Neil Kinnock, Mr Osborne explained.

He continued: “Now that consensus, which is so important for our security and reliability as an ally, risks being shattered again by an unholy alliance of Labour’s left-wing insurgents and the Scottish nationalists.

“This isn’t an argument about the past – the return of the unilateralists to British politics threatens our nation’s future security. In a world that’s getting more dangerous it would be disastrous for Britain to throw away the ultimate insurance policy that keeps us free and safe.”