How does it happen that Scottish Nationalism walks and talks as if it’s able to call terms over an independence referendum which opinion polls suggest it would lose? A major reason for the SNP’s sweep to absolute majority last May was the inadequacy of the Scottish Labour Party. At Devolution, such was Westminster complacency, only one first-rank Labour politician went to Holyrood: Donald Dewar. Since his death in 2000, the party has been led by what Scots call numpties, five of them over eleven years, remembered for the impact they didn't have.

Against them, Alex Salmond, dry, bright, good-humoured, lacking the usual blood rancour, has been like an Old Firm team matched against Stranraer. In consequence, even when put on the spot by David Cameron over referendum dates, his assurance made many commentators ask if the prime minister, in getting a climbdown, wasn't taking risks.

If Labour is serious about preserving the Union, a strong Labour voice has to be heard, asking difficult questions: on status, currency, taxation, debt, membership of the EU, all the economic responsibilities in fearsome detail. Alistair Darling stands there looking obvious, the man to lead Scottish Labour and speak for Union. He spoke up sharply on the Today programme on Wednesday. ‘The last thing I think Scotland needs,’ he said, ‘is for this to be posed as somehow an SNP government in Edinburgh up against a Tory government in London.’ He will, it is said, be one of the ‘main faces’ of the pro-Union campaign. That campaign can only be fought in Scotland: time, then, for Darling to give up his seat in Westminster and head for Holyrood?