DOUGLAS Ross has been "dropped to the subs bench" as the Scottish Tories draft in Ruth Davidson to promote the Union after a poll predicted a supermajority for pro-independence parties.

The Panelbase research, for the Sunday Times, put the SNP on track to win a majority of one in May’s election, with other Yes parties set to gain.

The poll found the Greens are on course to gain two seats on the regional list, while Alex Salmond’s Alba Party was forecast to win six.

The results would give pro-independence parties 79 of the Scottish Parliament’s 129 seats, ramping up the pressure on Boris Johnson to agree to a second referendum.

READ MORE: Poll predicts Tories will be biggest losers as Holyrood gets 29-seat Yes majority

After the poll, Davidson told Unionists: “As a direct result of the pro-UK vote splitting and some votes going to small parties, the SNP are on course for a majority and the nationalists on course for a ‘super-majority’ that they would use to hold another referendum.

“It is now mission-critical for the future of the United Kingdom that we unite if we’re going to stop an SNP majority. It has never been more important that pro-UK voters stick together, just like we did in 2016.

“Analysis shows that backing the biggest opposition party is our only option to stop an SNP majority.

“No matter who you support in your own constituency – and I want people to vote for their local Conservative candidate – the only way to stop an SNP majority is by using your party list vote for the Scottish Conservatives.”

The SNP said bringing back Davidson, who will soon leave Holyrood for the House of Lords, showed "desperation from the Tories".

SNP depute leader Keith Brown said: “Douglas Ross has failed so badly in his short time as Scottish Tory leader that when the campaign goes into panic mode, they have dropped him to the subs bench and rolled out Baroness Ruth Davidson to be Boris Johnson’s representative in Scotland.

“He is used to being on the side-lines in his refereeing career, but now he’s there in his political career too – if the situation was so ‘mission-critical’, why is he not the man in the middle?

“It is desperation from the Tories that the only option they have left is to wheel out Baroness Davidson before she skulks off to her £300-a-day job in the unelected House of Lords – she is the democracy denier in chief.

“In just over four weeks, the people of Scotland can re-elect Nicola Sturgeon as First Minister and put Scotland’s future into Scotland’s hands, not Boris Johnson’s by giving both votes to the SNP."

READ MORE: 'We must take our future into our own hands': Humza Yousaf makes case for indyref2

The Scottish Conservatives said: "A new poll shows that if the pro-UK vote splits, the SNP will win a majority. It has never been more important that pro-UK voters stick together, like we did in 2016. The only way to stop an SNP majority is by using your party vote for the Scottish Conservatives."

The poll also put support for independence at 51%, once undecided voters are excluded. It is the fourth poll in a row to put Yes in the lead. Some 54% of Scots want indyref2 to be held in the next five years, within the next Scottish parliamentary term, according to the research.

In the constituency ballot, the SNP were backed by 49% of respondents, the Tories 22%, Labour 20%, LibDems 6% and Greens 2%.

On the regional list, the SNP were on 39%, Tories 21%, Labour 17%, Greens 8%, Alba 6% (+6) and LibDems 5%. George Galloway’s All for Unity were also backed by 4% of those surveyed.

Seat projections are: SNP 65 (+2), Tories 24 (-7), Labour 20 (-4), Greens 8 (+2), Alba 6 (+6), LibDems 5 (no change), All for Unity 1 (+1).

Professor John Curtice said Panelbase’s results were “good news” for Alba, but a drop of just 2% in support would mean they would fall to one MSP.

The polling expert said: “Alba may be on the cusp of recording a creditable performance and coming away largely empty-handed.

“Although most of the seats the party could win with a 6% tally look as though they would be secured at the expense of the Unionist parties, our projection suggests that a couple might otherwise have been won by the SNP or the Greens.

“Even with an estimated 49% of the constituency vote, that is not a possibility the SNP will regard with equanimity.

“Such a result in the constituencies could still leave the party a seat short of an overall majority and reliant on winning a vital list seat to achieve what has come to be regarded as a crucial target.”

READ MORE: Alex Salmond to set out route to independence at Alba campaign launch tomorrow

He added that despite Nicola Sturgeon’s “both votes SNP” call, 9% of SNP backers in the constituency vote indicated they would vote Alba on the list and as many as 10% would opt for the Scottish Greens on the list.

He continued: “Alba is appealing to a section of the nationalist movement that wants a rapid timetable for indyref2 and which still admires Salmond.

“As many as 70% of Alba supporters want a referendum within 12 months compared with 48% of SNP list voters and 35% of Green voters.

“While 93% of those who back Alba believe that Salmond is ‘a fit person to stand for election’, only 13% of SNP supporters and 15% of Green voters take the same view.

“Salmond’s personality has enabled him to create a new party out of nothing.

“However, it may now also constrain what the party can hope to achieve.”