Last spring the Conservative minister, Nick Boles, noticed something exercising his constituents in Lincolnshire, in the English Midlands. Whatever their gripes with his party, they knew the Labour opposition could only govern after the 2015 general election with the parliamentary complicity of Scottish Nationalists.
And how they hated the idea. The MP had never known such a doorstep sensation, with voters irrespective of age, sex and class seething at talk of separatist influence at UK level.
Smelling an unanswerable line of attack against Labour, Boles drove to London to confer with Lynton Crosby, the Tories’ campaign director whose research, it turned out, had picked up the same sentiment.
The party spent the subsequent weeks talking up a deal between Labour and the Scottish National Party, which the SNP did nothing to talk back down. Thus were Labour's existing flaws sharpened in English voters' minds. How could a leader as shaky as Ed Miliband stand up to the SNP's formidable Nicola Sturgeon? Why entrust the economy to two parties of the left?
What germinated in Lincolnshire streets and airless focus group rooms grew into a lethal campaign, and now something much more important. British politics rotates around an unofficial non-aggression pact between English conservatism and Scottish nationalism. As antagonistic as any two movements in the land – culturally, ideologically – they nevertheless have a mutual strategic interest in each other’s success that neither side can admit.
As long as Tories govern in London, nationalists in Edinburgh have an ogre against which to define themselves and mobilise their voters. They can run Scotland and wear the rebel colours of opposition at the same time.
While gaining from this insider-outsider status, they can promote independence as the ultimate hedge against never-ending Conservative rule from Westminster, which also doubles up as something to blame for perceived blemishes in their own administrative record.
Defeat Tories
Meanwhile, as long as the SNP commands a virtual monopoly of parliamentary seats in Scotland, it is nearly impossible for Labour to defeat the Tories in a UK-wide election. And the harder it is for Labour to win, the more the party favours a life of ideological indulgence by way of consolation.
Labour members chose the ageing socialist Jeremy Corbyn as leader last autumn not as a way back to credibility, but as a source of pleasure while impotent. The Tories can rest on historically lavish poll leads because Labour has given up, and Labour has given up because the SNP is so strong.
A principled unionist cannot object to a UK government that hinges on a Scottish party’s votes. England’s emetic reaction to the mere prospect of SNP clout in Westminster last year amounted to a dismal prognosis for the union.
Still, Sturgeon will hardly worry about that, and even some Tories, when pressed, only want to preserve the UK in the same way that most people want to lose weight. The tangible reality of power matters more than the still-distant dread of national break-up.
No, the status quo suits both parties too much to disrupt, even if they knew how to go about such a thing. They are two columns propping up a political structure that shelters their interests.
Lost territory
The anguish is all Labour’s. The party can only get around its systemic exclusion from power by reclaiming lost territory in Scotland.
If Corbyn flunks that challenge – and polls ahead of May’s Scottish elections suggest he will have a hard enough time keeping the Tories in third – it should explode the idea that Scots are wildly left wing. There are cross-border differences, but they centre on identity first and ideology second.
Of course, Sturgeon will continue to clash with Tory prime minister David Cameron over nuclear weapons, budgets and the timing of the EU referendum. These grievances are real. The parties are so dissimilar in every way that journalistic coverage of parliament has turned into a kind of anthropology.
But if two prize fighters can insult each other monstrously while keeping a cold eye on the profit they make from the other’s existence, the two deftest politicians in Britain can perform a similar feat of cognitive dissonance.
There is something of boxing’s orchestrated raillery about Tory-SNP hostilities nowadays. The real competition for each side has always been Labour, and they have managed to lock it out of power. Only Scottish independence itself – which would give nationalists their existential prize – could suit either of these parties any more perfectly.
– (Copyright The Financial Times Limited 2016)