Euan McColm: It’s not the number of nationalist MPs that really counts

So, those calling for a second referendum on the UK’s membership of the EU have got one after all.

Boris Johnson meets Nicola Sturgeon at Bute House. If he wins the election he will definitely turn down any request for an independence referendum. Picture: Lisa Ferguson

We might be calling the vote on 12 December a general election and politicians might be muttering about health and education and what have you, but when the UK goes to the polls, the key issue upon which we will be making our feelings known is Brexit.

Will we send a majority of Tories back, enabling Boris Johnson to take the UK out of Europe under the deal he struck last month or, if he wishes, to use his parliamentary might to overturn legislation preventing a no-deal exit? Or will we – unlikely as it may now seem – return a majority Labour government, allowing Prime Minister Jeremy Corbyn to hold a second referendum, offering the choice of leaving with a deal or remaining?

Perhaps – and I accept this is the most unlikely of all possible outcomes – Liberal Democrat leader Jo Swinson will become our next prime minister and Brexit will simply be cancelled.

The stakes are high for all leaders, but for Johnson, the implications of failure are especially great. If he wins that majority, he’s home and dry, but polls told us the Tories would win a majority in 2017 and this did not come to pass. If this outcome is repeated and Johnson ends up, yet again, leader of the largest party in a hung parliament, the parliamentary impasse over Brexit that has persuaded MPs of the need for another general election – the fourth in less than a decade – will be re-established. If Johnson remains PM in those circumstances, he can expect his opponents to continue to hamstring him over the UK’s departure from the EU, making his premiership a miserable grind.

This, I think, would be the most entertaining outcome, but I daresay it wouldn’t do much by way of providing much-needed certainty over Brexit.

But while Brexit may be the central issue under consideration for voters, here in Scotland there’s another big constitutional question at the heart of this general election.

For SNP leader Nicola Sturgeon, the result in December will be all about Scotland’s place in the UK. The First Minister has, since succeeding Alex Salmond after defeat for the Yes campaign in 2014’s independence referendum, expended a great deal of energy explaining to Scots that we are becoming increasingly persuaded of the merits of breaking up the UK. Inconveniently for her, poll after poll has failed to show that this is true.

Recently, however, support for independence appears to have crept up. The nationalists might not yet have the majority of Scots onside – let alone the 60 per cent the First Minister’s people once briefed would be necessary for her to call a second referendum – but the tide is moving slowly in their direction.

And so the result of the coming general election is of huge importance to Sturgeon’s project.

We can, of course, assume that the SNP will win the majority of seats in Scotland. So dominant are the nationalists that they took 53 of Scotland’s 56 Westminster seats in 2015. And even after losing 21 of those constituencies in 2017, the SNP remained by far the largest Scottish party at Westminster.

But simply winning most seats in Scotland in December is not the goal. If Sturgeon’s SNP is to make real progress towards another referendum, the party will have to win a clear majority of votes. This will not be easy.

Even when the nationalists swept aside all but three of their opponents in 2015, they did so without winning a majority of the popular vote. This fact undermined any SNP claim that another independence referendum was necessary.

The result in 2017 hardly helped that SNP argument. Even senior party figures such as Deputy First Minister John Swinney conceded that the push for another referendum had cost the nationalists seats.

After a dozen years in power at Holyrood, the SNP remains seemingly untouchable by its opponents but the membership is becoming increasingly impatient about a lack of progress towards another referendum.

Sturgeon tells members that she wishes to hold another independence referendum next year, but the Scottish Government has no right to initiate such an event. When and if another referendum takes place is a matter for Westminster. Sturgeon may insist that there will be another vote on Scotland’s place in the UK next year but she cannot possibly guarantee such a thing.

If Johnson wins a majority in December, he will not waver from the current position of the UK government that a second independence referendum is a non-starter.

If Corbyn wins a majority, then he will have no reason to play along with SNP demands for another kick of the constitutional football. If Labour ends up the largest party in a hung parliament, however, then Sturgeon will find she has cards to play.

What the SNP really needs is for a majority of Scots to vote for pro-independence parties in December. The general election may, for the most part, be a rerun of the European question, but in Scotland it is a chance to revisit the matter of independence.

If the SNP, the Greens, and whichever fringe pro-independence parties that put up candidates come through the process without winning more than half the popular vote, it’s difficult to see how Sturgeon gets another referendum up and running.

Even a majority of votes for nationalist parties wouldn’t guarantee indyref2 but it would certainly bolster the First Minister’s case that one should be held.

After a prolonged period of unshakeable discipline in the SNP, cracks are beginning to appear. Some now wish Sturgeon to take a more aggressive approach, perhaps even declaring an election win as grounds to begin independence negotiations.

Such a course would be a recipe for disaster. It would create huge conflict in the SNP and the law would declare any claim of independence meaningless.

Right now, the most that Sturgeon can do is try to maintain momentum for the nationalist project. If nationalist parties win an overall majority in Scotland next month, she will have kept the train on the tracks.