‘Play the Scottish card’ was the title of the SNP’s 1987 manifesto.  It was accompanied by posters showing the leaders of the other ‘British’ parties as jokers.  

Not all Scots were amused. Hebridean Presbyterians promptly admonished the Nats for associating themselves with the wickedness of gambling and on polling day their Western Hebrides constituency was lost in an election that saw the SNP pick up only three seats. 

It is worth recalling not only how far the SNP’s fortunes have improved since then (estimates suggest that by 13th December the party will have between 40 and 50 MPs) but also just how much their central strategy remains the same.  

Indeed, the deep devolution of public sector provision to Holyrood has not only made playing the Scottish card the instinctive option, but the inevitable one.  What else is there to demand from Westminster but another vote on how to leave it? 

Whatever her gifts, Nicola Sturgeon has not the natural countenance of a poker pro.  When yesterday she played the ace that she had been flashing, in clear view, all along, she provided the Conservatives with their anticipated cue to update their 2015 tactics.  The image of a diminutive Ed Miliband in Alex Salmond’s breast pocket is now substituted with Corbyn poking out of Sturgeon’s sturdier tailoring.  

This is upping the stakes.  Stoking alarm at the prospect of a minority Labour government forced to dance to a Scottish tune was perceived to have played well for David Cameron during the 2015 election.  But only in England.  

It did little for the party’s fortunes north of Carlisle.  Despite the collapse of the Scottish Labour vote in that first general election since the 2014 Scottish independence referendum, Ruth Davidson (who had been Scottish Conservative leader since 2011) did even worse than had her predecessor, Annabel Goldie, in 2010.  In 2015, the Tories’ share of the Scottish vote fell from nearly 17% to below 15% and returned a solitary MP.

Will this time be different? Even if Scottish voters did not like the hint of an anti-Celtic dog whistle in the Tories’ 2015 messaging about the horrors of making Alex Salmond kingmaker, that general election came only eight months after the Scottish IndyRef.  Securing a second such referendum from Prime Minister Miliband would have been either an extraordinary coup or a terrible miscalculation by the Scottish Nationalists. Scottish voters with unionist sensibilities didn’t really buy it as sufficient threat.

But by 2017, the SNP’s appetite for a second IndyRef was returning. This made Ruth Davidson’s appeal as the guardian of a re-endangered Union in that year’s election considerably more plausible.  When the alternative was Jeremy Corbyn, Scotland’s unionists knew which party was better able to contain Nationalist demands and the Tories duly recovered their position as Scotland’s second party.  

For them, the 2019 re-match is as badly timed as it appears fortuitous for the Nationalists.  With Alex Salmond’s trial on charges of rape and sexual assault scheduled for the New Year, the SNP realises that this December could well be ‘Peak Nat.’  Why else would they have been so helpful in backing Boris Johnson’s bill to get around the Fixed-Term Parliament Act? This leaves the Tories defending many slender margins with only an interim leader in Jackson Carlaw to lead them into the ambush.  In 2017, it was the Scottish Conservative revival that secured Theresa May’s continuation in office. Will their retreat this time rob Johnson of the slender margins by which he may scrape home?

Carlaw leads his wary forces wearing battered amour. The Prime Minister’s Brexit deal has further weakened the belief among the more ardent Scottish unionists – who feel kinship with their Ulster brethren – that he makes an effective campaigner against the SNP.  Johnson’s defenders’ may respond that – for all its unionist inconsistencies – the Brexit deal he has secured will nevertheless shore-up the Scottish Tory defences better than the alternative prospect of no deal.  

Whichever of these is less damaging, the brazenness of Nicola Sturgeon’s determination to use a hung parliament to secure a second IndyRef at least breathes air back into Tory lungs – north and south of the Tweed.  

It does so because the Sturgeon gamble could easily succeed.  For, in a hung parliament, Jeremy Corbyn will have but two viable options for securing a parliamentary majority. The first is doing a deal with 40+ SNP MPs in return for a second Scottish independence referendum. The second is a pact with 30+ Lib Dem MPs whose price is Corbyn’s head.  For the Labour leader, there is no great dilemma here.

In deciding to throw caution aside and identify both the SNP and Labour with the holding of a second IndyRef, Sturgeon has played into Johnson’s hands. The UK has endured its three-and-a-half years of constitutional uncertainty. The potency of the ‘Get Brexit Done’ message appeals not just to diehard Leavers but to a wider, battle-weary desire to move on. Sturgeon’s gambit now allows the Tories to portray Labour as the agent of uncertainty, plunging the country into not one referendum but two.  

Labour strategists would have preferred that Scotland’s first minister had played her cards closer to her chest, at least for just a few more weeks.  But why would she? Like the Brexit Party, the Scottish National Party is only about one aim, and the clue is in the name.