Jeremy Corbyn's closest ally in Scotland has said he is "absolutely convinced" those in favour of unilateral UK nuclear disarmament will win the argument.

Labour MSP Neil Findlay clashed with party colleague Jackie Baillie at Holyrood today over the best tactics to rid the world of nuclear weapons.

Two other Labour MSPs, Malcolm Chisholm and Elaine Smith, signed an SNP motion opposing the renewal of Trident - in a foretaste of the wider debate expected at the Scottish Labour Party conference later this month.

Mr Findlay, Mr Corbyn and Shadow Scottish Secretary Ian Murray favour unilateral UK disarmament in the hope it will convince other countries to follow suit, but they are at odds with Labour's multilateralist support for Trident renewal.

UK Labour reaffirmed its support for Trident at its conference last month but Mr Corbyn caused confusion by admitting he would never launch a nuclear attack.

Scottish Infrastructure Secretary Keith Brown, a former marine, said it is "deeply immoral" for Labour to advocate spending £100 billion on weapons it would not use.

Ms Baillie insists scrapping the Faslane nuclear submarine base would cost 11,300 jobs and affect many of her West Dunbartonshire constituents.

But Mr Brown said the constituency's backing for Scottish independence and overwhelming rejection of Labour at the general election suggest her constituents disagree with her.

Mr Findlay said: "I oppose nuclear weapons and I oppose the renewal of Trident.

"I appeal to those who want to see the world rid of nuclear weapons whether they are unilateralists or multilateralists - after all we are all on the same side but we simply disagree on tactics - to work together to further develop a credible and serious defence diversification plan and strategy."

He added: "If we do that and take forward this argument and win it - I am absolutely convinced we will win it - we need to build that alliance to take the argument across society and across the political divide in order to eradicate these weapons from the world."

Ms Baillie said: "I believe in multilateral nuclear disarmament, and I don't think anybody in this chamber or indeed outwith it would want to see nuclear weapons being used.

"I want all nations to give up nuclear weapons and my ambition, and I know it is one that is shared across this chamber, is actually to achieve global zero.

"Whilst I absolutely respect the position of unilateralists, I don't believe that that action alone will trigger other nations to reduce their weapons."

Ms Baillie said "even the dogs in the street in my community know" the size of the job losses that the closure of Faslane would bring.

Mr Brown said: "Jackie Baillie says everybody knows the benefits of her argument including the dogs in the street.

"The SNP MP Martin Docherty got around a 10,000 majority in her area at the general election.

"Her area voted Yes to independence. I think the arguments about nuclear weapons were very prominent in those campaigns."

He added: "I would condemn the Labour Party's current position which is to say we would spend £100 billion on nuclear weapons and not use them - that is deeply immoral."

SNP MSP Christina McKelvie, who lodged the motion to scrap Trident, said: "Three members of the opposition benches - Neil Findlay, Elaine Smith and Malcolm Chisholm - have signed this motion because they too want to see investment in people instead of weapons of mass destruction.

"I have to commend them all for their integrity and their willingness to rise above the political mudslinging that remains at the background of this debate."