Scottish Labour party delegates have backed a vote to scrap the UK's Trident nuclear missile system, which is based at Faslane naval base on the Clyde.

A motion at the party's conference in Perth calling for the system not to be renewed was supported by an overwhelming majority. 

Both party members and unions voted 70% in favour of the motion.

It means Labour now holds different positions on the issue north and south of the border.

However, UK leader Jeremy Corbyn supports not renewing the system.

Analysis by BBC Scotland Political Editor Brian Taylor

The Scottish Labour party now has a policy of opposition to Trident. The extent of the vote makes that verdict incontestable. It will permit Labour members to counter the SNP - who have a long-standing anti-Trident position.

But in practice, what next? Scottish Labour routinely opposed nuclear deterrence in conference votes throughout the 1980s and 1990s, with zero effect.

Might that change now? Not in the short term. The replacement of Trident is a Westminster decision and the Conservatives have a Westminster majority.

Beyond that? Might Labour throughout the UK now adopt an anti-nuclear stance? Certainly it has a leader in Jeremy Corbyn who favours such an approach.

Still, as one seasoned party observer noted in Perth, Scottish Labour now has a supporter of multilateral disarmament leading a party which has endorsed unilateralism. It is conceivable, said the observer, that the UK party ends up offering the mirror image.

After the vote, a spokesman for Mr Corbyn said: "Scottish Labour Party members have spoken. That will now feed into the wider UK Labour debate and review of defence policy."

Mr Corbyn's backing for unilateral disarmament puts him at odds with Scottish Labour leader Kezia Dugdale, who instead supports the removal of nuclear weapons on a multilateral basis.

But Labour's only surviving Scottish MP insisted the party could have different policies on renewing Trident north and south of the border.

Shadow Scottish secretary Ian Murray said moves to make the party in Scotland more autonomous meant it could "have a different position on anything it wants".

Scottish activists made Trident a priority issue for a policy vote at the conference after it received the most votes of the 17 issues proposed for debate. 

Nuclear non-proliferation

The conference debate was opened by Stephen Low, of Unison and Glasgow Southside Constituency Labour Party, who said renewing Trident "is something that we do not need and cannot afford".

Mr Low said: "Its purpose is to detonate a nuclear warhead above a city, killing everyone in its radius.

"There are other facts about Trident, but that's the central one, and one we should never forget."

He added: "When it comes to the real threats to this country, things like terrorism, things like cyber attacks, things like climate change, Trident is utterly, utterly useless."

"We shouldn't want Trident renewal even if it were free, but of course it is not free, it comes at an utterly bewildering cost."

Trade union Unison is committed to getting rid of Trident.

During the debate, Davina Rankin from the union told delegates there was no military argument for it and no moral case.

Pat Rafferty, from Unite, which represents Faslane workers, said Britain should take lead in nuclear non-proliferation.

Mr Rafferty said the argument for non-renewal must go "hand in hand" with a jobs diversification plan and the billions saved from Trident could help workers and be used against a "crisis" in industry and the public sector.

However, BBC Scotland has learned that the vote has exposed a rift in the union, with workers at Trident's home base frustrated with the national position taken by Unite's national leader Len McCluskey.

GMB Scotland, which also represents shipyard and defence workers, made clear its support for renewal of Trident.

The union's Gary Smith told the conference the "glaring omission" from the debate was what alternative jobs would be for those working at the base.

Mr Smith said: "This debate is a nonsense and frankly an utter indulgence."

He said the GMB was standing against "Alice in Wonderland politics".

MSP Jackie Baillie, whose Dumbarton constituency includes the naval base, said: "Faslane is the biggest single-site employer in Scotland. More than a quarter of West Dunbartonshire's full-time workforce are employed there in good quality, well-paid jobs."

She hit out at the SNP, who want to move the Trident submarines from the Clyde, describing this stance as "nimb