SNP 'must gain seats from both Tories and Labour' to help secure IndyRef2

The SNP must gain seats from the Tories as well as Labour at the 2019 general election if the party is to strengthen its mandate for IndyRef2, a constitutional expert has said.

Nicola Sturgeon is expected to demand a Section 30 order - the legal mechanism which would allow Holyrood to stage another plebiscite - before the end of the year if her party, as expected, makes gains at Thursday's election.

But the Centre on Constitutional Change - an academic think-tank based at the University of Edinburgh - said if the Nationalists wanted to strengthen their mandate, they would have to make advances at the expense of the two big parties.

"The SNP argues that it has a mandate to hold another independence referendum on the basis of the 2016 manifesto, and asks voters to support this mandate," wrote Coree Brown Swan in an blog post

Nicola Sturgeon speaks at a pro-independence rally in Glasgow last month. Picture: John Devlin

“They argue that a vote for the SNP is an endorsement of their position that the people of the Scotland have the right to choose their own future and it is for the Scottish Parliament, not Westminster, to decide when that referendum will be held.

"Limited Scottish polling suggests that the party is set to gain seats, but who will they gain them from and how will these gains be interpreted?

"The SNP is unlikely to replicate its 2015 success but it is still expected to do well in the forthcoming election.

"However, to be a win for the SNP and reinforce its mandate, they need to take seats from Conservatives rather than just Labour."

What constitutes a legitimate mandate to hold an IndyRef2 has become a key battleground between the SNP and the Conservatives.

Scots Tory leader Jackson Carlaw claimed today that the SNP would need to win more than two million votes if the party ever wants to be able to claim a mandate for a second independence referendum.

But Swan, a post-doctoral research fellow at the Centre, said the IndyRef2 question was not going away.

She continued: "Whoever wins on Thursday, Scottish independence will remain a live issue, and an increasingly complex one for both the UK government and the SNP.

"While a Conservative victory might bolster the SNP’s case for independence, a Conservative government may be less likely to engage in dialogue over the terms of a referendum, and Brexit as envisaged by the Conservatives may make the practicalities of an independent Scotland more complicated, and costly.

"Labour victory, or a hung parliament, might place the Scottish government in a strong negotiating position to secure a second referendum, but may remove some of the impetus around this debate.

"Polling suggests any future referendum is likely to be a close one and will be shaped by dynamics at the Scottish, British and European level."