Two Scottish Labour MSPs have backed an SNP call for the renewal of Trident to be scrapped.
Neil Findlay and Malcolm Chisholm have signed a motion lodged at Holyrood by SNP MSP Christina McKelvie.
The motion calls for "investment in people instead of these weapons of mass destruction".
It comes after delegates at Labour's conference in Brighton voted last week to avoid a debate on the issue of Trident renewal.
That meant the party remains committed to "a minimum, credible, independent nuclear capability, delivered through a continuous at-sea deterrent".
But its new leader, Jeremy Corbyn remains opposed to the UK's nuclear weapons and sparked criticism from some of his own shadow cabinet when he said he would not use weapons of mass destruction under any circumstances if he became prime minister.
Mr Corbyn and his Scottish Secretary Ian Murray have said they will continue to voice personal opposition to Trident despite the continuing party policy.
Mr Chisholm has a history of backing the SNP's calls to scrap nuclear weapons.
He resigned from former Labour first minister Jack McConnell's cabinet in order to vote with the SNP in a previous motion condemning the renewal of Trident in 2006.
Mr Findlay is seen as being a close ally of Mr Corbyn who pledged to scrap Trident during his unsuccessful bid for the Scottish Labour leadership last year.
Current Scottish Labour leader Kezia Dugdale has pledged to hold an open debate on Trident at the Scottish Labour conference later this month.
Ms McKelvie's motion raises concerns about the Chancellor's announcement that £500m will be spent on ensuring the continuation of HM Naval Base Clyde at Faslane as a nuclear submarine base for the next generation of Trident nuclear weapons.
The motion also criticises the fact that the announcement came before the UK Parliament had made a decision on the next generation of nuclear weapons.
It states: "Money such as this would be far better spent on supporting many in society including people who are sick or disabled, young people and pensioners in constituencies such as Hamilton, Larkhall and Stonehouse, where those in vulnerable positions have been so negatively affected by welfare reforms that have been continued by the current UK government and the previous UK coalition administration.
"This continued move toward a next generation of nuclear weapons is at odds with the beliefs of the majority of the Scottish population and elected members."
Ms McKelvie welcomed the Labour MSPs' support but said it "only increases confusion about Labour's position both north and south of the border".
She added: "Last week Jeremy Corbyn admitted that Labour may go into next year's Scottish elections without a clear position on Trident, meaning he expects people to support Labour when they have no idea what they're voting for.
"But given that Labour's UK leader, their deputy leader in Scotland, their only Scottish MP and now two senior MSPs making clear that their party should vote with the SNP against Trident, Kezia Dugdale is looking increasingly isolated."
The motion, which has also been signed by SNP colleagues, Green and independent members, will be the subject of a short member's debate after first minister's questions on Thursday.