INDEPENDENCE has become “the settled will of the majority” in Scotland as a new poll reveals record support for Yes, Keith Brown has said.

The SNP depute leader said a clear majority for pro-independence parties next year – as predicted in new work by Ipsos Mori – means no Westminster leader can stand in the way of a second referendum.

The polling firm’s latest Scottish Political Monitor, run in partnership with STV News, found 58% of those who would vote in such a ballot would choose Yes – the highest level of public support for constitutional change ever recorded.

Almost two-thirds – 64% – said the UK Government should allow another independence referendum to be held within the next five years if the SNP wins a majority of seats in next year’s Scottish Parliament elections.

However, responding to the poll, Downing Street once again renewed its opposition to a second independence referendum.

Asked about the findings at the lobby briefing today, a Number 10 spokesperson said: “The issue of independence was settled when the Scottish people voted decisively to remain part of a strong United Kingdom, it was a once in a generation vote and it must be respected ... the UK Government will continue to uphold that decision.”

Only a third of people disagreed with the proposition that a new poll should be held within the next Holyrood term if the SNP win a majority in May.

The research – carried out by phone with more than 1100 voting-age Scots earlier this month – further reveals the SNP has a “very strong lead” in voting intention for both the list and constituency contests at 47% and 58% respectively.

Another 9% said they would vote Scottish Greens on the regional list.

Nicola Sturgeon was the only main party leader to record a positive approval rating, while Boris Johnson’s was the lowest ever seen for the PM in Scotland by the pollsters.

Emily Gray, managing director of Ipsos Mori Scotland, said the poll “will put a spring in the step of nationalists but makes grim reading for Unionists”.

She went on: “Our poll suggests that there will be significant public pressure for the UK Government to transfer powers to the Scottish Parliament to hold a second independence referendum if the SNP win a majority at next year’s Holyrood elections.”

Brown said: “This is a landmark poll which shows that independence has now become the settled will of the majority of people in Scotland.

“Faced with the chaotic and incompetent government of Boris Johnson and a Westminster system which treats Scotland as an afterthought at best, more and more people are deciding that the best way forward for Scotland is as an equal, independent country.

“And if there is a clear majority for pro-independence, pro-referendum parties in next year’s election – as this poll shows there would be by some considerable margin – then no Tory or any UK Government has the right to stand in the way.

“Quite simply, in those circumstances, the Tories would lack any moral or democratic authority whatsoever to try and block the will of the people, and it would not stand.

“Already, the Westminster wall of opposition to a referendum has started to crumble, with private acknowledgement that a result like this in next year’s election would have to lead to a referendum, and this poll will only solidify that growing view.”

He went on: “The SNP takes absolutely nothing for granted and we will redouble our efforts between now and next year’s election to retain the trust of the people.

“But it is clearer than ever that Scotland’s future lies as an independent country.”

The Tories are in second place with 19% in each category and Richard Leonard’s Scottish Labour are currently polling at 13% in each. For the LibDems, the figure was 8% across the board.

Greens co-leader Patrick Harvie MSP said: “It’s clear that the Scottish Greens constructive approach to opposition is appreciated by the public. From Scotland’s fairer tax system to the reversal of unfair exam grades and free bus travel for young people from next year, we’ve worked constructively to make Scotland a fairer country.

“This poll also shows support for independence at its highest ever point. It’s clearer than ever that the UK simply isn’t working for Scotland and that we must take our future into our own hands to build a better Scotland.”