SCOTLAND'S largest trade union's backing for a new independence referendum has been hailed as a "totemic moment" for the movement.

Members of the trade union Unison voted in support of a second independence referendum, with the SNP saying there was now "unstoppable momentum" behind a fresh vote.

Unison's decision came yesterday, just as hundreds of independence supporters gathered at a rally outside the Scottish Parliament to hear SNP MSP Stuart McMillan say there is "still a job to do" to garner support for Scotland to break from the union.

At the meeting in Glasgow, Unison's Scottish convener Lilian Macer said the body representing public service workers had backed calls for another vote, at a time to be decided by the Scottish Parliament.

She said: "This in no way pre-determines the views our members may take in the event of an independence referendum, but they should have the opportunity to express their views.

"Unison Scotland will take this decision into the wider trade union movement and, together with the Jimmy Reid Foundation, we will promote the debate at the forthcoming STUC congress in April 2020.

"Unison Scotland defends public services and those who deliver them and it is imperative that we explore the full range of options available to the people of Scotland."

The motion put to members stated that Unison "supports the call for a second referendum, at a time to be determined by the Scottish Parliament, by means of either a section 30 order or an amendment to the Scotland Act as a satisfactory means of transferring the power over independence referendums."

On Wednesday MSPs voted 64-54 in favour of a motion calling for a second referendum.

And on Thursday a YouGov poll suggested that a narrow majority of Scots may now support independence - with 51% backing Yes to 49% No, excluding don't knows.

However the survey also found 56% of respondents were opposed to having a referendum this year - with only 34% in favour.

SNP depute leader Keith Brown said there is now "unstoppable momentum" behind a fresh vote.

He said: "Unison is the latest respected body to support a transfer of powers so the Scottish Parliament can hold a fresh referendum at a time of its choosing.

"The democratic right of the people of Scotland to determine our own future cannot be ignored by Westminster.

"And the Constitutional Convention announced by the First Minister on Friday will provide an opportunity for organisations such as Scotland's trade unions to come together with elected politicians around that democratic right."

The Scottish Greens described Unison's endorsement as a "totemic moment" for the independence movement.

Co-leader Patrick Harvie MSP said: "Unison represents members of different party political persuasions, but its decision today to back an independence referendum, at a time to be determined by the Scottish Parliament, recognises the democratic deficit that we currently face.

"This can only be resolved by putting the question of Scotland's future back to the people."

The decision by Unison - with its strong ties to the Labour Party - to call for another referendum is at odds with Scottish Labour which does not want a further vote.

In the debate last week Scottish Labour leader Richard Leonard said that "the people of Scotland don't want another independence referendum any time soon".

But the front-runner to lead the UK Labour Party, Sir Keir Starmer - who is supported by Unison, has said he opposes independence but if the SNP won the Holyrood elections next year, "any government would have to consider it".

Questioned on Scottish Labour's reaction to Unison's decision, the party's constitution spokesman Alex Rowley MSP said: "Polling this week has shown that the Scottish people do not support the holding of another referendum at this time, especially with the Brexit process still far from resolved.

"Protecting Scotland's interests in this process is of paramount importance.

"We understand that 10 years of austerity and five more years of Boris Johnson does lead to further despair, but the creation of a separate Scottish state will not resolve the underlying economic issues."

A spokesman for the Scottish Conservatives said: "All the time Nicola Sturgeon wastes on her indyref2 obsession would be better spent on the crises her party have created in Scotland's schools, hospital and public services.

"The SNP must end their constitutional obsession and get back to the day job."