Pollsters are expecting a significant upsurge in tactical voting at next week's general election as hundreds of thousands of Scots look set to cast their ballots to stop a party they oppose from winning seats.

Rachel Ormston, research director at polling company Ipsos, said that survey findings pointed to almost one in four people - 23% - of voters poised to vote tactically.

She said the figure was up from 13% in survey Ipsos carried out just ahead of the general election in December 2019.

Some 4,012,700 Scots were registered to vote, according to the latest figures published in April 2023.

Should voter turnout be at 68% in line with the 2019 election, it would mean 2,728,636 people will vote in Scotland, meaning 627,586 people will vote tactically.

Ipsos asked people to choose whether they were voting for a party that most represented their views or whether they were voting as the party they support had little chance of winning and they were voting for another party to keep a further party out. Field work was carried out from June 3 to 9.

"Nearly one in four are saying that they are planning to vote tactically to keep another party out," Ms Ormston said.

"It is worth while saying this is quite a bit higher than a similar point in the 2019 campaign when it 13%."

Asked why there has been such a significant increase in voters considering voting tactically, she said: "There has been a big shift in patterns of voting intentions in Scotland. Support for the SNP has fallen and support for Labour has gone up.

"Support for the Tories too has fallen."

She added that potentially different types of tactical voting appeared to be going on depending on which constituency voters lived.

"Scotland is unusual in that there are almost no Labour/Tory races. The races are Labour/SNP, SNP/Tory and SNP/Lib Dem. So the kind of tactical voting that is going on may be different in different constituencies in Scotland.

"Some of it may be driven by some dissatisfaction with the Scottish Government, and push back again the SNP, while in other areas it may be [voters thinking] 'which party is best placed to remove the Tories.'"

Ms Ormston said among Scottish voters there were also differences in what type of voters intended to vote tactically.

She said their poll in June found that among people who voted in the 2019 general election, some 31% of Conservatives intend to vote tactically, compared to 22% Labour 2019 voters and 13% of SNP 2019 voters.

She added that tactical voting tended to be higher among pro-UK voters than independence supporters with 32% of those who would vote no if there was another indyref tomorrow were considering voting tactically, compared to 14% of those who would vote Yes.

"There seem to be two dimensions to tactical voting in Scotland, potentially unionist voters trying to work out which party will most likely unseat the SNP and also anti-Tory tactical voting as well," she said.

Officially all political parties say they want voters to vote for their parties but last week Labour was hit by a tactical voting row when the party's candidate for Aberdeen South (a contest between the SNP and the Conservatives) in next week's general election Tauqueer Malik was captured on footage caught by a Ring doorbell telling a voter the party secretly supported the Tories in Aberdeen South in 2019 in a bid to defeat the SNP.

Scottish Labour's deputy leader Dame Jackie Baillie denied the party had done so.

"It's completely untrue," she told The Herald.

"We fight for every single vote in every single seat. I don't advocate Labour voters voting for anybody else. It was untrue and a very stupid thing to say."

Scottish Conservative leader Douglas Ross in April last year got embroiled in a tactically voting controversy when he appeared to suggest

Tory supporters should vote Labour at the general election if that party’s candidate is best placed to beat the SNP.

In an interview with the Telegraph Mr Ross said people should “do what’s best for the country” to loosen the SNP's grip on Scotland.

He said: “The public know how to tactically vote. I will always encourage Scottish Conservative voters to vote [for us] but I think generally the public can see, and they want the parties to accept, that where there is a strongest candidate to beat the SNP you get behind that candidate.

“If parties maybe look beyond their own narrow party agenda and do what’s best for the country and for me as Scottish Conservative leader, what would be best is if we see this grip that the SNP have on Scotland at the moment is loosened.”

He later seemed to row back on his comments, saying that his call for tactical voting was a plea to Labour and Liberal Democrat supporters to back his party.

Ms Ormston said the risk for parties who unofficially may endorse tactically voting was that they could get support among voters who may not back them again.

"Sometimes parties do encourage it as it can help them in the short term," she said.

"But the risk is that tactical voting could be soft support in the longer term. If people vote tactically for you rather than because they believe in your policies, then the parties cannot rely on that vote again.

"For instance, if Labour is benefitting for tactical voting this time around that support doesn't necessarily [remain] in 2026."

Ms Ormston said the latest Ipsos UK wide poll, published last week, suggested there would be more tactical voting across the UK generally, with 19% of voters indicating they may do so next week, compared to polling Ipsos carried out from November 19 to 25 2019 showing 13% of people would do so.