DAVID Cameron would “not push the nuclear button”, Jeremy Corbyn has suggested, as delegates gathering for Scottish Labour’s three-day conference in Perth are being urged to back calls for a set-piece debate on Trident.

The Labour leader caused headlines last month at his party’s UK conference when he made clear that there would be no circumstances under which he would launch a nuclear strike.

In an eve of conference interview with The Herald, Mr Corbyn was asked if, by his declaration, he had not made Labour’s policy review redundant because, if the party leader announced he would not push the nuclear button, then, even if the party supported Trident’s retention and replacement, the deterrent to our enemies would cease to exist.

Mr Corbyn, a leading member of CND, replied: “I suspect David Cameron would not push the button either, actually. I don’t argue the deterrent point, I argue the world would be better off if we all adhered to the non-proliferation treaty and nuclear states took steps towards nuclear disarmament as they are required to by that treaty...”

The Prime Minister says he is fully behind maintaining Trident and replacing it with a new generation of nuclear submarines, which new analysis estimates has risen in price from £100 billion to £167bn. A final vote at Westminster on renewal is due by spring.

Earlier this month, Mr Cameron insisted he would be willing to push the nuclear button and claimed Mr Corbyn’s answer to the question had “undermined our national security”.

He said: "If you...believe like me Britain should keep the ultimate insurance policy of an independent nuclear deterrent, you have to accept there are circumstances in which its use would be justified.”

While a head of steam was raised over the debate on Trident at Labour’s UK conference in Brighton last month, it never happened due, some suggested, to a lack of support from the trade unions, which back the nuclear deterrent because of the thousands of defence jobs it maintains.

Today, a similar process on choosing topical debates will be undertaken at the Scottish Labour conference, where some senior figures would also like the deeply divisive issue of Trident not to be debated.

Earlier this week, the powerful GMB union urged Labour members to reject a possible motion opposing Trident renewal. Acting Secretary Gary Smith said scrapping the missile system would cost thousands of highly-skilled defence jobs.

But left-wing MSP Neil Findlay, who ran Mr Corbyn’s leadership campaign in Scotland, has urged delegates to support a Trident debate, saying it was "too important an issue to duck". If approved, it will take place on Sunday.

The vote would be seen as an early test of plans to make Scottish Labour a more autonomous arm of UK Labour; seen by Kezia Dugdale as essential to killing off once and for all the view that the party north of the border is a “branch office” of the London HQ.

But the proposal has already come in for criticism for the lack of consultation with parliamentary colleagues before Mr Corbyn’s and Ms Dugdale’s “joint statement of intent” earlier this week and for the lack of policy detail. One senior party figure branded it a “dog’s dinner”.

However, the UK party leader insisted it was not a done deal. “The autonomy issue is…open to discussion, debate and rule change, if necessary.”

He added: “I want the party to recognise this huge surge of membership(now almost totalling 400,000) does provide a different dynamic and a different set of opportunities…I’m not planning a top-down(leadership); quite the opposite.”

Meantime, Shadow Scottish Secretary Ian Murray in his keynote speech today will draw on his own personal background to insist Labour is the party of aspiration and will accuse the UK and Scottish Governments of “abdicating their responsibility to level the playing field”, putting at risk the prospects of the next generation of Scots.

The Scottish Labour leader will give her keynote speech tomorrow.