Scottish Labour has taken its biggest lead over the SNP for almost a decade, according to a poll published today.

The survey found a growing number of independence supporters switch their voting allegiances to Anas Sarwar's party amid mistrust of both First Minister Humza Yousaf and his predecessor Nicola Sturgeon.

The research by Norstat, which recently acquired the polling firm Panelbase, put Labour on 36% , up three points since its last poll in October, with the SNP on 33%, down four points.

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It is Scottish Labour’s strongest poll performance since the day after the independence referendum in 2014 and would hand Sir Keir Starmer a significant boost in his attempt to achieve a majority government at Westminster by returning 28 MPs — ten more than the SNP.

Scotland will lose two MPs under the boundary changes that come into effect at the election and have 57 MPs rather than the current 59.

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The SNP, which secured 48 constituencies in 2019, would win 18 seats under the results, according to analysis by Sir John Curtice, the polling expert and professor of politics at Strathclyde University.

This number would be 11 less than the majority of Scottish seats to provide a mandate to begin negotiations for a referendum, as he SNP agreed at its conference last October.

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The survey was commissioned for the Sunday Times and is the first poll conducted since the SNP WhatsApp deletion scandal and comes as Ms Sturgeon prepares to give evidence to the UK Covid inquiry for a full day this Wednesday.

It also found the public had less confidence in Mr Yousaf and Ms Sturgeon than in Anas Sarwar, the Scottish Labour leader. Mr Starmer’s trust rating sits between the two SNP figures.

Mr Yousaf returned a net trust score of minus 25 with Ms Sturgeon ranked at minus 19 and Mr Sarwar's at minus 17. Mr Starmer's trust rating was minus 24, while Prime Minister Rishi Sunak had the lowest at minus 48. Scottish Tory leader Douglas Ross's trust rating was minus 38.

Last week, the Covid inquiry in Edinburgh heard that ministers and officials discussed key policy decisions over WhatsApp messages, despite protests that no official business was carried out on informal media.

Ms Sturgeon and others have not retained all of their messages despite assurances given by her in a media briefing in 2021. The former first minister was able to provide some Whatsapp messages to the inquiry from other people.

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Ms Sturgeon was arrested and released without charge last June in connection with an investigation into the SNP’s finances. Her home and the party headquarters were searched by police in April, while Peter Murrell, her husband and the former SNP chief executive, and Colin Beattie, the former treasurer, were also arrested, questioned and released.

Professor Curtice said that “yes” supporters were continuing to switch to Labour.

“Whereas at the end of 2022, shortly before Nicola Sturgeon’s resignation, 80% of current yes supporters were saying that they would vote SNP in a UK general election, now that figure has fallen to a new low of just 63%,” he said.

“The SNP need to overcome two key problems. The first is the relative unpopularity of Humza Yousaf. Around one in four [26%] of those who voted SNP at the last Westminster election in 2019 believe that he is doing a bad job as first minister, and they appear especially likely to be unwilling to vote SNP again.”

The poll put the Conservatives on 16%, down two points, while the Liberal Democrats were unchanged on 7%. Reform UK won 4% and other parties collectively had 4%. This would see the Tories retain their six seats in Scotland, while the Lib Dems’ current yield of four MPs would rise by one.

The next Holyrood election will take place in 2026 and, according to the poll, Mr Sarwar would be likely to become First Minister despite the SNP being on course to secure the most seats.

The SNP would return 47 MSPs, according to Professor Curtice, by winning 36% in the constituency vote and 30% on the proportional regional list.

Labour would have 40 MSPs with 31%  and 29%; the Tories 24 MSPs with 16% and 19%; the Greens ten MSPs with 5% and 9%; and the Lib Dems eight MSPs with 7% on both votes.

This would produce the first unionist majority at Holyrood since 2007 and almost certainly see Mr Sarwar enter Bute House. 

Norstat interviewed 1,007 adults in Scotland aged 16 or older from January 22 to January 25.

Commenting on today's poll Scottish Labour deputy leader Jackie Baillie said: “Poll after poll shows that the Scottish people want change.

"The people of Scotland have had enough of both of Scotland’s failing governments and recognise that the change we need is a UK Labour government.

"Scotland is being failed by two bad governments who want you to believe this is as good as it gets, and Scots have put them on notice.

“At the General Election, Scotland can lead the way on delivering the change that the UK needs and maximise Scotland's influence by delivering Scottish Labour MPs across the country and booting the Tories out of Downing St.”