A subject we have returned to time and again in this column over the last year or so is the way the pandemic has exposed the chaotic state of the UK’s ‘territorial constitution’ – who governs what, basically.

Rather than being able to pursue a joined-up approach to combating Covid-19, the Government was instead reduced to trying to stitch together a ‘four nation’ strategy with the devolved administrations.

But Rishi Sunak’s visit to Scotland this week shows that these tensions may yet have some distance to run. Alison Thewliss, the SNP’s ‘shadow chancellor’, has urged him to apologise for winding down furlough and other economic interventions ‘early’.

The root of the problem is as follows. Control over lockdown and other pandemic control measures is in the hands of the devolved governments – that’s how Mark Drakeford managed to close ‘non-essential’ supermarket isles. But control over the financial assistance that makes things such as furlough possible is controlled by the Treasury.

Even in the most fevered devocrat imagination, it could scarcely be otherwise – not unless Edinburgh and Cardiff wished to finance the pandemic on their own resources, which seems doubtful. We could not have devolved administrations simply voting themselves British cash without accountability to our British Parliament.

But it does raise the prospect of yet another row, with Drakeford and Nicola Sturgeon accusing the Government of dragging Scotland and Wales out of lockdown on England’s schedule.

Nor is this the only constitutional minefield the Chancellor will have to navigate. Assuming it isn’t abandoned for other reasons (including basic generational justice), Whitehall sources suggest he could face a backlash over the constitutional dimension of his proposals to hike National Insurance in order to fund social care.

What constitutional dimension? Well, NI is a tax collected on a UK-wide basis, whereas social care is a devolved competence for which the Government is only responsible for England. This is thus, apparently, the first time a British tax has been increased explicitly to pay for an England-only spending commitment.

Of course, any increase in social care spending will generate Barnett consequentials, so the other nations would get the money ‘back’. But nobody likes a tax hike, especially when the SNP can weave a grievance into it. It’s also a bit of an unforced error, as the link between the tax increase and the spending is only in the Government’s rhetoric and could have been avoided.

Sunak is talking up the ‘strength of the Union’, and rightly so. As Chancellor, he commands one of the few truly powerful British departments, with the ability to make its presence felt in every corner of the country. It is therefore especially important that he is properly prepared to do battle with the nationalists – be they SNP or Labour.