Labour would gain more than 20 seats at the next Westminster election and the SNP lose 22 under current forecasts, according to an analysis of the latest opinion poll.

The survey is a boost for Sir Keir Starmer who has been visiting Scotland this week and was yesterday campaigning in Rutherglen and Hamilton West where a by-election is expected in early October.

Research by YouGov showed the SNP still had the most support of the political parties on 36 per cent, down a point since April, when the company last polled voting intentions in the general election. Labour’s vote share increased by four points over the same period to 32 per cent.

Analysis of the results by Sir John Curtice, professor of politics at Strathclyde University, suggested these figures would see Starmer win 22 seats in Scotland under the current boundaries. The party has just one at the moment.

Such a result could make a significant difference to Starmer’s chances of becoming prime minister with a majority in the House of Commons.

By contrast, the SNP would lose 22 seats and return 26 MPs, in what would be a severe dent to the authority of party leader Humza Yousaf in his first full-blown election as the party’s leader.

But Mr Yousaf saw a boost in his popularity in the latest poll, after support for him dropped when he first became first minister.

Mr Yousaf's personal rating is up by 11 points since June, when YouGov last tested the popularity of Scotland’s political leaders, although he still returns a score of -16.

Sir John said that Mr Yousaf has started making progress at winning over voters but pointed out that only 52 per cent of people who voted SNP in 2019 think he is doing well, well behind the levels enjoyed by Nicola Sturgeon when she was in post.

Anas Sarwar, the Scottish Labour leader, and Douglas Ross, the leader of the Scottish Conservatives, also received boosts. The latter increased his score by eight points to -36 while Mr Sarwar became the only party leader to return a positive rating, of +4, after adding seven points to his popularity.

The Tories would retain the six constituencies the party currently holds despite dropping by two points to 15 per cent. Such a result would not ease pressure that is currently building on Douglas Ross, the Scottish Tory leader.
The Liberal Democrats, whose support also fell by two points to 6 per cent, would win five seats, an increase of one.

“Labour are now clearly breathing down the SNP’s neck in the battle for Scottish seats at the next UK general election,” Sir John told the Times. 

“But the foundations of Labour’s advance rest on the party’s success in advancing at the expense of the beleaguered Conservatives, not just in winning over Yes supporters from the SNP. Unfortunately for Mr Yousaf that is a competition over which he has relatively little influence.”

According to the poll, 21 per cent of people who voted Conservative in the 2019 general election would switch to Labour at the next UK-wide contest.

Sir Keir hailed Mr Sarwar’s performance as he addressed constituents in Rutherglen and Hamilton West yesterday, where he said the constituency “really matters” to Labour’s aims to win the general election.

“When I think about where we where when Anas took over to now, it’s like night and day,” he said.

Mhairi Black, the SNP’s deputy leader at Westminster, said that Sir Keir should be “embarrassed campaigning for a so-called fresh start in Scotland,” adding: “The Labour leader has publicly signed up to a Tory manifesto for the status quo — more Westminster austerity, more economic carnage and more misery for Scottish households.”

Support for independence nudged up to 42 per cent, an increase of three points since April. The proportion of people who said they would vote to retain the Union fell by one point to 44 per cent with 8 per cent undecided, 3 per cent saying they would not vote and 2 per cent refusing to express their view.

However, independence slipped one place to seventh on people’s list of priorities with just 17 per cent of people saying it should be a key aim for the Scottish government. It came behind health, the economy, education, climate change, housing and social care.

“Unionists would be making a mistake to assume that Labour’s rise and the SNP’s political troubles signal the death knell of the demand for independence,” Sir John said.

“Support for Yes continues to run at just under 50 per cent, and most Yes voters still want a referendum at some point in the next five years. Whoever wins the next Westminster election will still have the future of the Union as a key item on their risk register.”

The poll also suggested that there would be another pro-independence majority after the next Holyrood election, with the SNP winning 57 seats and the Greens ten. Labour would return 38 MSPs to comfortably overtake the Conservatives whose representation at Holyrood would almost halve, to 16 MSPs. The Liberal Democrats would win eight seats under this scenario.

YouGov interviewed 1,086 people aged 16 and older in Scotland between August 3 and 8.