Is time running out for the union as the case grows for a new independence vote?

Are postal voters bolder? Does the solemnity of polling stations cow voters into having second thoughts? Because of the pandemic, there will be far more postal voters than ever in the Scottish elections on 6 May – almost a quarter of the electorate. It’s easier to be adventurous with a ballpoint at your kitchen table. The radio next to the teapot said last week that Boris Johnson and his English Tories were going to veto Scottish bills aimed at strengthening the rights of the child and of local authorities, even though both were passed unanimously by Scotland’s parliament, which could prove a significant landmark. It grows easier to vote for the three parties that want another independence referendum.

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Nicola Sturgeon’s SNP, Patrick Harvie’s Greens, Alex Salmond’s new-born Alba. Two – three, if Alba overcomes its dire beginning – will make a majority in the Scottish parliament. Uncannily, the SNP and Sturgeon seem to have emerged from the uproar over the Salmond inquiries with nothing worse than deep scratches on the paintwork. Public grillings of Salmond and Sturgeon, merciless media bombardment – and yet trust in the SNP and its leader did little more than bob down and up again. The independence camp, its minds made up, apparently stands where it stood before, counting roughly half the pollsters’ samples.

So, after 6 May, Johnson will almost certainly face a Scottish parliament claiming a mandate to call another referendum. That claim will almost certainly be dumped in front of the supreme court. Holyrood will implore the court to declare its mandate legal. Westminster’s barristers will remind the court that it has accepted the almighty principle of “parliamentary sovereignty” – the right of a Commons majority to overrule anything it doesn’t like. Constitutional lawyers will go into an orgy of Zoom as they consult one another on the doctrines of Dicey, Bagehot and Lord Cooper of Culross (the Scottish judge who declared parliamentary sovereignty was an English nonsense that had no place north of the border).

In reality, Johnson will face three options. The first is the gutsiest: “Bring it on!” Grant Scotland leave to hold the referendum, fight it furiously and win. He’d still have a chance of success. The case for the union, so wanly expressed in England, remains vigorous in Scotland; voters are still split almost 50-50 over independence, with Yes a whisker ahead. Drawbacks: first, that “Bring it on!” looked better for unionists 18 months ago, before the pandemic; second, Johnson can’t get worked up about anything Scottish. As prime minister of England, he has unexpectedly become quite popular. Why waste energy “up there”, where they seem to regard him as a joke or a menace? Boring!

The case for the union, so wanly expressed in England, remains vigorous in Scotland

Second option: do nothing. Win the supreme court case, establishing that no Scottish constitutional referendum can be legal unless the UK government licenses it by operating section 30 of the Scotland Act (as David Cameron did with the 2014 independence referendum). Then tell the Scottish government and the Yes campaign to go away and shut up. Sturgeon has said repeatedly that a vote for independence has to be legal, in UK terms, to be internationally recognised. So dare her to throw away caution and run a wildcat plebiscite on her own. That might well be boycotted by the unionist camp. If so, a “Yes” outcome could lead towards the same horrible turmoil that engulfed Catalonia in 2017.

The third option: dirty tricks. The 2014 referendum was licensed under the “Edinburgh agreement” between Salmond and Cameron, allowing Salmond considerable influence over its terms. This time, Johnson could offer another section 30 permission, on conditions the Scottish government would be suicidal to accept. One condition might be to insist on London’s right to dictate the words on the ballot paper. No more Yes or No to “Should Scotland become an independent country?” Insert a third question: the choice of near-federal powers over the economy plus slivers of foreign policy and immigration. In short, something like the old “Devo Max” option many Scots would have gone for in 2014 if it had been available. Another cunning possible condition would be to allow Scots living elsewhere in the UK to take part.

In 2014, expat Scots in London or Liverpool were loud in their outrage at being denied a voice in their nation’s future, when Europeans living in Scotland were encouraged to vote. The idea sounds democratic but it’s disingenuous. The huge Scottish diaspora (well over 700,000 in England alone) is heavily unionist and most of its members – though Scotland-born – are well-rooted residents rather than migrants temporarily away from home.

Another cunning possible condition would be to allow Scots living elsewhere in the UK to take part

These are, of course, wrecking amendments. Any third option on the ballot paper would almost certainly ensure that no clear majority for independence could emerge. And letting Scots in the rest of the UK take part would decisively bump the scales towards the union. At the same time, and it’s part of the calculation, “disenfranchising” Anglo-Scots could make a Sturgeon government in Edinburgh look undemocratic to the outside world, especially to the European Union, which an independent Scotland would want to rejoin.

At this stage, it’s a fair guess that Johnson will go for some variant of the third option. If he can make granting a referendum sound like a magnificent gesture of reconciliation and statesmanship, he can present Sturgeon’s rejection as utterly unreasonable. Yet reject it she must. Professor Ciaran Martin, “constitution director” in the Cabinet Office from 2011 to 2014, sees Westminster’s intention to block any Holyrood request for a referendum as the moment when the union ceases to rest on consent and relies on force of law: “What England wants, England gets.”

That leaves confrontation. On one side, the Johnson government is clawing back authority across the UK, undercutting devolved ministries with new institutions run from London. Its challenge to the two Holyrood bills on the rights of the child and of local government is the latest example. But on the other side the desire for independence, though growing incrementally, seems to be hardening. Among Scottish 16- to 35-year-olds, it stands at 72%. Tick-tock!

Long ago, when the campaign for self-government began, sceptics put a mocking question: “So what will you do when England says No?” The easy answer now could be: “We’ll wait.” But there’s a feeling that time for waiting may be short. The United Kingdom is an old ice floe and the climate is warming fast.

• Neal Ascherson is a journalist and writer