The Scottish Conservatives will urge supporters to vote Labour in key constituencies at the general election under plans to “end nationalist dominance” in Scotland.

In an unprecedented system of tactical voting, Douglas Ross's party are inviting rivals to co-operate in a “vote smart” strategy in a bid to shore up unionist votes in rural parts of Scotland while lending Labour support in the central belt, which stretches from Glasgow to Edinburgh.

However, the offer is likely to anger members of the UK Conservative Party who trail Labour in the polls and face a gruelling battle to keep Rishi Sunak in Downing Street.

Asked today about what Mr Sunak might think of the proposed electoral pact, the Scottish Conservative MSP Stephen Kerr told the BBC's Sunday Show: "The Prime Minister as with all Conservatives is committed to the idea we put our country first.

"The people of Scotland will make their own minds up about how they vote."

READ MORE: Humza Yousaf faces 15 rebel SNP MSPs prepared to challenge government

He said he didn't know if the Prime Minister knew about the tactical voting plan call, adding that he himself wasn't involved in any discussions about it.

A Scottish Conservative spokesperson said: “We will always urge voters to back the Scottish Conservatives in each and every election.

“However, the electorate is sophisticated and aware of the dynamics in individual constituencies.

“In a host of seats, particularly in rural areas, the Scottish Conservatives are the only party who can defeat the SNP and we are confident that voters, for whom the Union is the priority, understand that.”

Stephen Flynn, leader of the SNP at Westminster, said the proposed pact showed the "better together band" between Labour and the Conservatives, when the parties formed an alliance to campaign against independence in the 2014 referendum, was getting back together.

“It will surprise no one to see the dreadful better together band announcing their reunion - a band that made endless empty promises to people across Scotland because they couldn't muster a positive case for the broken union," he said.

“The disastrous duo have been standing shoulder to shoulder in councils and in Holyrood ever since but, be in no doubt, people will not be fooled by this latest effort. Neither of the Westminster parties are even pretending to care about Scotland's interests anymore." 

He added: “Quite frankly, it’s a struggle to spot the difference between the Tories and Labour - the pro Brexit, pro cuts, anti Scottish democracy Labour Party is a pale imitation of the right wing Tories.

“Scotland deserves far better than either of the Westminster parties' contempt of ignoring our interests at every turn - the SNP will always champion Scotland’s voice and seek to build a fairer, more prosperous future as an independent country, free from Westminster control for good.”

The proposed unionist pact comes as new polling for The Sunday Times shows the SNP is losing support since Humza Yousaf replaced Nicola Sturgeon as First Minister.

A Panelbase survey carried out after Mr Yousaf’s appointment suggests the party would lose 14 seats at Westminster and Holyrood’s pro-independence majority would disappear if the results were replicated at elections.

The Conservatives believe they will hold onto all six Westminster seats next year and sense opportunities to gain ground in the north and south of Scotland since the election of Yousaf. Polling confirms this with Labour set to be the biggest beneficiaries of SNP decline, increasing their vote share at Westminster by three points to 31 per cent.

The Conservatives would remain on 19 per cent, the Liberal Democrats drop by two points to 5 per cent and support for other parties increased by two points to 6 per cent.

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A Scottish Conservative source told the Sunday Times: “With the election of Humza Yousaf as SNP leader there is clearly an opportunity to end nationalist dominance at next year’s general election and make them pay the price for ignoring Scotland’s real priorities.

“But that requires Scots to vote smart to maximise tactical voting. That means putting normal party politics to one side and voting for the candidate most likely to beat the SNP.

“That means, for example, Conservative voters in Glasgow backing Labour, while Labour voters in Aberdeenshire vote for the Conservatives.”

The first electoral test for tactical voting and for Yousaf as SNP leader is the potential by-election in Rutherglen & Hamilton West.

Recent Tory focus groups conducted in rural seats suggest little evidence of a Labour revival outside of their historic strongholds.

Key Tory targets on current boundaries are understood to include Angus, Ayr, Carrick & Cumnock and Gordon.

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The Panelbase poll put support for the SNP at 39 per cent in a UK-wide vote, a fall of four points from the company’s research for The Sunday Times last month and the first time the party has fallen below 40 per cent with the pollster since the December 2019 general election.

Sir John Curtice, the polling expert, said it suggests that the SNP would return 34 MPs, compared to the 48 it won just over three years ago.

In this scenario, Labour would return 14 MPs, a significant increase from its current single representative north of the border and a boost to Sir Keir Starmer’s bid to be the next prime minister, while the Tories would retain their current six constituencies and the Lib Dems would add one to win five seats.

“SNP parliamentarians at Holyrood and Westminster overwhelmingly backed Mr Yousaf for the party leadership,” Mr Curtice told The Sunday Times.

“But unless he turns around his party’s fortunes soon, they may begin to wonder whether they made the right call.”

He added that the results showed “the loyalty of Yes supporters to the SNP is being eroded” as backing for the party fell while the proportion of people who desire independence remained static at 46 per cent.

Support for the Union was 49 per cent with 5 per cent unsure. When don’t knows are excluded this would see 48 per cent of people vote Yes in a referendum and 52 per cent vote No.

After a divisive first week in post which saw Kate Forbes, Mr Yousaf’s leadership rival, quit government rather than be demoted and Keith Brown, the SNP deputy leader, sacked from cabinet, Mr Yousaf will spend Holyrood’s April recess planning a series of announcements to be made on parliament’s return.

He has said that his main focus will be on the cost of living, which chimes with public opinion. Seventy-two per cent of people said that the economy should be one of Mr Yousaf’s three main priorities with the same proportion selecting the health service, the first minister’s old brief.

Independence came fifth in people’s list of priorities with 25 per cent of those surveyed selecting it in their top three, behind education (39 per cent) and social care (28 per cent).

According to the poll, people do not have faith in the First Minister to turn things around, with just 19 per cent confident that he will improve the Scottish government’s performance. More than half, 52 per cent, were not confident with 21 per cent neutral and 8 per cent unsure.

The next Holyrood election is not due until 2026 but Panelbase’s findings will make for uncomfortable reading in Bute House and SNP headquarters.

In constituencies, 37 per cent of people said they would vote for the SNP, a fall of 6 points. Labour received 33 per cent support, up six points; the Conservatives 17 per cent, up one point; the Lib Dems 8 per cent, up one point; the Greens 5 per cent, up one point; with 4 per cent voting for other parties.

On the regional list, 31 per cent said they would vote SNP; Labour secured 27 per cent; the Tories 20 per cent; the Greens 10 per cent and the Lib Dems 6 per cent. Alba returned 5 per cent in a result that would see them return two MSPs, according to Curtice’s analysis.

The SNP group would drop by 16 to 48 MSPs while Labour would go up by 15 to 37, the Conservatives would fall by five to 26 and the Greens and Lib Dems would each add two members to return ten and six MSPs respectively.

This would mean there would be a majority of unionist politicians in Holyrood for the first time since 2011.

Panelbase interviewed 1,089 adults in Scotland between March 28 and March 30.