Trade unions are on course to clash over the future of the Trident nuclear deterrent at Scottish Labour's conference later this week.

Anti-Trident Labour activists are canvassing for support from the unions ahead of a vote on the issue at the event in Perth.

Unison, the UK's largest trade union, remains committed to getting rid of the deterrent, which is based at Faslane on the Clyde.

It has been reported that Unite, which represents workers at the Faslane base, is also poised to come out against its renewal.

Previously, Unite leader Len McCluskey had indicated the union supports renewal because scrapping the weapons system would cost its members jobs, but the Scotland on Sunday newspaper reported the Unite Scottish delegation will vote to get rid of nuclear weapons if it receives assurances that action will be taken to protect jobs.

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

It has written to members in the defence sector in advance of the conference, which runs from Friday to Sunday.

Gary Smith, GMB Scotland acting secretary, said: "GMB has vigorously defended our members in the defence manufacturing sector and we will make the case for Trident renewal at the Scottish Labour Party conference.

"The 40,000 defence workers in Scotland are as vital to our national security as the Armed Forces. Without the skills of the workforce in the yards on the Clyde and Rosyth, the Royal Navy could not defend the nation.

"It makes no sense to abandon our long-standing overall defence strategy unilaterally for solely political reasons. That goes for Trident and the jobs at Faslane and Barrow."

He added: "There will be talk about defence diversification at the Scottish Labour conference but, frankly, it is pie in the sky.

"The Scottish Labour Party and the Scottish Government need to get real on jobs. Without defence work there will be no Clyde shipyards and Falmouth would probably face closure."

The potential clash of the trade unions could mirror divisions on Trident policy within the Labour Party itself.

The adoption of an anti-Trident position by Scottish Labour at the conference would be seen as a boost for UK leader Jeremy Corbyn, who is a long-time supporter of scrapping the nuclear weapon.

Mr Corbyn suffered a blow to his leadership after a bid to vote on Trident was rejected at the party's UK conference last month.

Currently trade unions hold 50% of the votes at conference, with the remaining half coming from the Scottish party's 73 constituency parties.

The majority of the union votes are held by Unite, Unison and the GMB.

SNP MSP Bill Kidd, co-president of Parliamentarians for Nuclear Non-Proliferation and Disarmament, called on Scottish Labour leader Kezia Dugdale to support the abolition of Trident at the conference.

He said: "Kezia Dugdale would be well advised to take heed and join with the SNP by opposing these abhorrent weapons outright - rather than doing everything she can to duck the issue.

"Warm words from Jeremy Corbyn simply aren't going to cut it - it's time that the whole Labour party saw sense and stood against this reckless and immoral spending on weapons of mass destruction."