These 13 Scottish seats helped the Tories cling to power in 2017. Here's how people can stop them this time

In 2017, the Conservatives had their best general election performance in Scotland since before Margaret Thatcher was prime minister.

Increasing their tally of seats from one to 13, the seats won by Scottish Tories were instrumental in helping former PM Theresa May hold on to power. After all, if May had not been within 10 seats of a majority, then even a deal with the Democratic Unionist Party wouldn’t have helped her stay in Downing Street.

In the run-up to the election, polls have been increasingly volatile, with some predicting a Tory majority and others leaning towards a hung parliament.

North of the border, a resurgent Scottish Nationalist Party is hoping to target the Tory vote and reduce the tally of 13 significantly. This could, in certain circumstances, deprive Boris Johnson of a majority.

This means that what happens in Scotland, particularly in seats currently held by Scottish Conservatives, could be crucial in determining the future of the UK.

The number of seats won by the Conservatives in Scotland could be the difference between a working majority or minority, and another election next year.

So what should Scots who want to stop a Tory majority –​ and are open to the idea of voting tactically –​ do?

Nicola Sturgeon has been keen to point out that the best way to stop the Tories is voting SNP.

But is she right?

Looking purely at the numbers, it would seem so.

In every single Tory-held seat in Scotland, the SNP is the main challenger

Here’s a list:

• West Aberdeenshire and Kincardine
• Gordon
• Banff and Buchan
• Ochil and South Perthshire
• Ayr, Carrick and Cumnock
• Angus
• Dumfries and Galloway
• Stirling
• Berwickshire, Roxburgh and Selkirk
• East Renfrewshire
• Dumfriesshire, Clydesdale and Tweeddale
• Moray
• Aberdeen South

In Stirling, the Tories have a majority of just 148. In Angus, the Tory majority is just 2,600, just as it is in Gordon.

In each of these 13 constituencies, the SNP is in second place. There are no Labour/Tory marginals and zero Tory/Lib Dem marginals.

Over the course of the election, there's been lots of talk about the importance of tactical voting. For Scottish supporters of Labour, the Greens and the Lib Dems, who want to vote tactically to stop the Tories, these numbers speak for themselves.

More: Viral tweet shows how tactical voting could cause Boris Johnson to lose his seat