A DE facto referendum must be contested as a Yes alliance, it has been claimed, after a survey suggested Scotland’s pro-indy parties would account for at least 50% of the vote at Holyrood.

A Panelbase poll found the vote share for the SNP, the Scottish Greens and Alba would amount to 51% of the Scottish Parliament constituency vote – and 50% of the regional vote.

The research, commissioned by the Alba Party, comes as the UK Supreme Court considers whether the Scottish Parliament has the power to hold an independence referendum.

If it decides Scotland can’t call a plebiscite, First Minister Nicola Sturgeon has vowed to fight the next election as a de facto referendum.

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The survey suggests the SNP, Greens and Alba would take 42% of the vote share at a UK level.

The next Westminster election is set to take place in January 2025, unless it is called earlier, with the next Holyrood vote set for May 2026.

According to Panelbase, the Tories would slip into third place in UK and Scottish elections, in both regional and constituency seats in Scotland.

If a UK General Election was held tomorrow, the poll found 42% of likely voters (excluding undecided) would vote SNP, 30% Labour and 16% Conservative. Alba and the Scottish Greens are both on 2%.

The National: Nicola Sturgeon has said that if the UK Supreme Court rules Scotland cannot hold an independence referendum she will fight the next election as a de facto referendumNicola Sturgeon has said that if the UK Supreme Court rules Scotland cannot hold an independence referendum she will fight the next election as a de facto referendum

In a Scottish Parliamentary election, the SNP saw an even higher share of the vote, with 45% of Scots (excluding undecided) saying they’d vote for the party with their constituency vote. Labour came second with 28%, while Tories were on 15%. Alba and Greens were both on 3%.

For the regional ballot, more than a third (37%) of likely voters (excluding undecided) would give their vote to the SNP if an election was held tomorrow. Labour came in second again at 26%, while the Tories were on 17%. Greens were fourth with 9% of the vote, LibDems on 7% with Alba on 4%.

The National:  FOR THE NATIONAL...Portrait of Chris McEleny, SNP deputy leadership candidate, pictured in Glasgow...  Photograph by Colin Mearns.9 August 2016.

Chris McEleny (above), Alba Party’s general secretary, told The National the research “shows that everything Alex Salmond said on a de facto referendum is correct – to win, it must be contested as a Yes alliance”.

The former first minister and Alba leader said this week that if the SNP fight the next General Election as a de facto referendum, it should be under something like a “united ticket.”

Salmond said: “You could fight an election with Scotland United SNP, Scotland United Greens and Scotland United Alba and then say: ‘This is clearly above political parties. This is just about the cause and case of Scottish independence’. That might work. It would be difficult, but it might work.”

Tasmina Ahmed-Sheikh, the chair of Alba, said the poll showed the party is within “touching distance” of gaining Holyrood seats.

She said: “The Unionist parties would love us to go away because it is their seats we would sweep up in the Scottish Parliament.”

The National: Mark McGeoghegan

Polling expert Mark McGeoghegan (above) said winning a pro-independence majority at the next election will be “extremely difficult”.

He told The National: “Pro-independence parties have won a majority of the Scottish Westminster vote exactly once, in 2015, when independence had been explicitly taken off the table.

“But [Alba’s] suggestion of a ‘Yes alliance’ – a formal pact between pro-independence parties, with its own joint branding – will be ignored by larger pro-independence parties precisely because they will feel that Mr Salmond’s involvement will make that job harder, not easier.

“Savanta ComRes’s political tracker has consistently found that Salmond is the most unpopular political figure in Scotland, their most recent poll found that three-fifths of Yes voters are unfavourable towards him.”

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The Glasgow University researcher added that it was unlikely that Alba’s polling numbers (at 4% in Scottish regional seats) would translate into seats.

The poll found Yes and No are neck and neck, with 49% of likely voters (excluding undecided) saying they would vote for independence while 51% said they would vote to remain in the UK.

On the monarchy, it found that 55% of Scots who voted in favour of independence in 2014 want to see the country become a republic with an elected head of state, while 31% back the royals.

Among 2014 No voters, 21% wanted a republic and 68% seek to retain the royals.

The SNP and Scottish Greens were approached for comment.