Scottish political leaders have accused George Osborne of pre-empting a potentially divisive vote on the future of nuclear weapons by preparing the Faslane naval base for the renewal of Trident.

Mr Osborne today said that a £500 million investment in the Clyde base is "partly to ready Faslane for Trident's replacement".

Just two Scottish MPs back replacing Trident, with 56 SNP MPs and Labour's shadow Scottish Secretary Ian Murray indicating they would not support its renewal.

Meanwhile, Scottish Labour leader Kezia Dugdale has set herself on a potential collision course with UK Labour by confirming she will bow to the will of Scottish party members on their support for Trident.

The party will hold an open debate on Trident at its conference in October, and Ms Dugdale confirmed the winning argument will become the position of the Scottish Labour Party.

Three of the four UK leadership candidates support renewal, but left-wing abolitionist Jeremy Corbyn is currently leading the polls.

Scottish Deputy First Minister John Swinney accused Mr Osborne of deliberately trying to stir up tensions in the Labour Party by making today's announcement less than two weeks before the leadership ballot closes.

He said the UK Government has prioritised nuclear weapons over welfare, but Mr Osborne hit back that Mr Swinney will soon have his own tax and welfare powers.

Scottish Liberal Democrat leader Willie Rennie accused Mr Osborne of being "provocative and premature".

Ms Osborne told BBC Radio Scotland's Good Morning Scotland programme the £500m investment is "partly to ready Faslane for Trident's replacement...to make sure that we remain a free democracy that is able to defend ourselves at the last instance".

He said: "In a very uncertain world, are we really content to throw away Britain's ultimate insurance policy?

"Can Nicola Sturgeon or Alex Salmond tell me what the world is going to look like in 2060, because that is when we are making this decision for? I don't think they can."

Mr Swinney said: "George Osborne is making this announcement today partly to stir it up within the Labour Party, to exacerbate some of the issues around the stance taken by Jeremy Corbyn.

"We've also had Scotland's sole Labour MP Ian Murray making clear that he would not vote for the renewal of Trident."

Mr Osborne "is making the wrong moral choice to essentially prioritise investment in nuclear weapons over the protection of some of the most vulnerable citizens of our country," he said.

Mr Osborne retorted: "If the SNP want to go to the Scottish people in the next few months and say, 'We're going to use these powers to raise taxes to have a bigger welfare system', then let them take that argument to the Scottish people."

Ms Dugdale, whose deputy leader Alex Rowley also wants to scrap Trident, confirmed that she would "absolutely" follow the wishes of the party if it votes to reject renewal.

"That would be the result of a democratic process, that would be the position of the Scottish Labour Party," she said.

She insisted a vote that went against the prevailing mood of UK Labour would not be divisive.

"It's devolution and that's a good thing, people want power to be closer to people," she said.

Mr Rennie said: "I think George Osborne is being rather provocative today by coming up in a very premature way.

"He's come up here in a big flash to try and provoke the anti-Trident sentiment amongst quite a large population in Scotland.

"We've not even had the debate on Trident. I would rather have seen that debate coming in a very reasonable and sensible way."

The final decision on the renewal of Trident isn't expected until 2016, but there is no obligation on the Government to give parliament a vote on taking the programme forward.

If a vote does take place, the Tories now have the political weight to force the issue through parliament, meaning renewal is highly likely to go ahead under the current Government.