The YouGov survey for The Times puts the SNP on course to win the next Holyrood election but indicates losses for the pro-independence parties and Labour returning as official opposition as the Conservative drop back into third place.
Based on the voting intentions of 1,135 Scottish adults questioned between October 2 and October 5, researchers predicted the SNP would secure 57 seats in a Holyrood election, down six from their 2016 figure.
The SNP’s independence allies the Greens would drop from from six to four, meaning there would no longer be a majority at Holyrood supporting independence.
First Minister Nicola Sturgeon pushed back plans for a second Scottish independence referendum after her party lost 21 seats at Westminster in June’s snap election but has said she remains committed to giving Scotland a choice on its future at the end of the Brexit process.
The poll found voters intentions signalled Labour would gain eight seats to reach 32 and move into second place, ousting the Tories who would remain unchanged on 31, while the Liberal Democrats would also remain static on five.
Nearly three quarters of Scots polled (72%) are pessimistic about how the Brexit negotations are going while 16% are optimistic and 12% said they don’t know.
Around one in six of those surveyed (59%) said they thought Britain was wrong to leave the EU, up two percentage points from April, while 30% said they thought it was the right decision and 11% said the don’t know, both of which had fallen one percentage point since April.
More than half of respondents (57%) said they were pessimistic about Britain’s future after leaving the EU, while 31% were optimistic and 12% replied they don’t know.
The SNP said the results, published on the eve of the party’s three-day Autumn conference, found support for the SNP higher than at the same point after previous Holyrood elections.
SNP Business Convener Derek Mackay said: “After 10 years into government, it’s a remarkable vote of confidence that the SNP outperforms itself in mid-term polling.
“And with the Tories falling back into third place, it’s pretty clear the Davidson bubble has well and truly burst.
“With Theresa May making a complete mess of negotiations, anti-Brexit sentiment in Scotland is getting even stronger, in face of the huge threat to jobs and living standards posed by the Tories, who should see sense and commit to protecting our place in the single market.”
Scottish Conservative constitution spokesman Adam Tomkins said: “This is another indication that appetite for separation across Scotland is on the decline.
“It also shows people who may have trusted the SNP even if they weren’t pro-independence are now abandoning the party.
“That is the cost of running a government which has obsessed with a single issue for its whole tenure, tossing everything else of importance to the side.”