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Scotland's largest trade union has backed calls for a second independence referendum.

A meeting of Unison's Scottish council has voted in favour of indyref2 at a time to be determined by the Scottish Parliament.

The motion voted on calls for the powers to hold a vote to be transferred to Holyrood from Westminster.

Nicola Sturgeon has reiterated her desire for another vote but Boris Johnson has rejected the suggestion.

Unison's Scottish convenor Lilian Macer 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 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."

On Wednesday, SNP and Green MSPs united at Holyrood to pass a motion saying a referendum should be held "on a date and in a manner determined by the Scottish Parliament".

However, the powers to hold a legally binding vote are reserved to Westminster.

Speaking on the BBC's Politics Scotland, Scottish Labour leader Richard Leonard called for an "open and honest" discussion about the implications of independence.

He said: "I understand given the prospect of five more years of a Boris Johnson government why some people are driven to anger and despair.

"We will listen to why Unison members reached that conclusion but I'm bound to say the prospectus put forward by the SNP and their growth commission report is one of a very hard dose of austerity that would lead to cuts in public services that Unison and other trade unions work in."

Image copyright Getty Images Image caption Boris Johnson has formally ruled out indyref2 and has called on Nicola Sturgeon to back his efforts to bring the UK together after Brexit

SNP depute leader Keith Brown MSP 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."

Scottish Greens co-leader Patrick Harvie MSP described the move as a "totemic moment for the independence movement".

He added: "Unison represents members of different party political persuasions, but its decision to back an independence referendum, at a time to be determined by the Scottish Parliament, recognises the democratic deficit that we currently face."

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."