Alistair Darling had a good banking crisis.

Unlike the financial system itself, the then Chancellor emerged from the catastrophe of 2008 with credit. He kept the show on the road when it seemed, for a while, that finally capitalism had hit the wall.

You could equally say, however, that Mr Darling doesn't deserve too many congratulations. He was part of the Labour Government that indulged and coddled the banks in their mad, criminal ways. He served when Gordon Brown was pulling the private pensions system to pieces and making a mockery of the state's alternative. In point of historical fact, British banking came apart at the seams on Mr Darling's watch.

You would think he might be cautious, then, about employing one of Labour's larger failures for the purposes of analogy. Not a bit of it. In an interview with a London newspaper, Mr Darling announces that a vote for independence could have consequences for Scotland worse than the 2008 crisis. No scaremongering on his part, then.

The chairman of Better Together/No Thanks (and certainly no Orangemen, thanks) says: "If we get it wrong, it will have a profound effect, not just on Scotland, but the rest of the UK. The stakes in the banking crisis were big; this is so much bigger." Mr Darling reaches his definition of "wrong", it seems, from the fact that independence would be irrevocable.

It's an interesting tactic. In the same interview, after all, the former chancellor assures us that "the devolution settlement is here to stay". Put aside the truth that no-one, least of all Mr Darling, has an earthly idea of what the future nature and shape of that settlement is likely to be: permanence can't be the issue. The objection is to the kind of change that would prise Scotland from Westminster's control.

According to the chief operating officer of No, the risks in that are nothing short of colossal. Mr Darling says, in summary: You thought the last few years were hellish while the British economy came within hours of collapse? Independence could be worse. Horses and children can count themselves frightened. The rest of us might be persuaded to ask who, if not a sovereign Westminster government, was supposed to be in charge when apocalypse loomed in 2008.

This is lurid stuff. It also marks another change of tack in the meandering voyage of HMS Nope. Not so very long ago, Unionist politicians such as the former Chancellor seemed to have abandoned their efforts to convince the Scots that, uniquely in the world, they could not possibly cope as citizens of an independent country. The question, we were told, was not whether Scotland could survive or thrive: it was simply a matter of being Better Together.

We might be prosperous, they allowed, just not as prosperous. No longer. Something worse than the worst crisis since the Great Depression is the selected yardstick.

The risks are no longer calibrated according to the assumed benefits of Union, but on a dial turned all the way up to "colossal". So the rhetoric resumes: Scotland couldn't cope. The Tories blame Labour for 2008; Labour blames international events; united, they tell us that the best hope of avoiding something still worse is to vote No.

But I forgot: theirs is a positive campaign. In his interview, Mr Darling lists his positive case as "jobs, pensions, social security". Mr Brown's various interventions in pension provision have been noted.

Unemployment is certainly "falling", but only if you pay no heed to the young, to stagnant wages, to zero-hours contracts, to part-time working, and to the relentless rise in the number of people forced to call themselves self-employed. As to social security, Mr Darling is bound to ask Iain Duncan Smith for a few supportive words.

These little difficulties are doubtless all the fault of the Tories. That, though, is a difficulty in its turn for the chairman of an at-all-times united No campaign. Does he mean we are Better Together no matter who is in charge at Westminster? Does he mean we benefit regardless, rough with the smooth? Or will all be well if we just vote No and wait a few short months until Ed Miliband leads Labour back to power?

Interestingly, Mr Darling hesitates to give assurances on that score. He says only, "I think we (Labour) can win" but judges that, in strange times, the next UK General Election remains too close to call. That's not exactly a ringing endorsement of Mr Miliband's efforts. It's not entirely inspirational, either, for those whose referendum votes might be influenced by the risk of another Tory government.

Theirs might be a short-term view, but it is a respectable short-term view. David Cameron approaches the independence argument with extreme caution because he is perfectly well aware of these voters. Mr Darling offers them a 50-50 chance. At a guess, that's not exactly what Scottish Labour is saying on the doorsteps.

If a senior figure concedes that the General Election is too close to call, I think we can take it hopes for Mr Miliband are not running sky high. Don't knock yourselves over with those feathers. Draw some conclusions, instead. Mr Darling is advocating the Union come what may, in all circumstances, under any version of Westminster's pick n' mix politics. That's his privilege, but it offers still another definition of what is meant by Better Together: the usual suspects. The former Chancellor calls it the best of both worlds. His world is the problem.

He prefers to talk instead about intimidation. Not, clearly, the menaces offered by the kind of politician who believes independence involves risks graver even than the greatest financial meltdown in living memory. Not, surely, the threats to Scotland's European status offered by a succession of Coalition ministers. Mr Darling is talking about the bullying of business folk by the SNP.

Or so it is alleged. Those prepared to corroborate the claim tend to have already declared themselves for No. In other cases, such as the allegation that Alex Salmond tried to suppress a report prepared by Scottish Financial Enterprise (SFE), the supposed victims tend to undermine the allegations. As Owen Kelly, Scottish Financial Enterprise (SFE) chief executive explained, Scottish Government ministers are perfectly entitled to express a view. It would be "odd" if they did otherwise. In this case, the SFE stated its position, published its report, "and the world moved on".

The intimidation claims are supposed to show what life would be like under the SNP jackboot. Putting aside the odd Labour belief that Mr Salmond's party is incapable of losing an election whether the country is independent or not, it makes a change from associating Yes voters with Nazis. That would be scary and, as we know, Better Together never, ever indulges in scares. Apart from the one about the sky falling in. The No campaign is negative: the clue is in that two-letter word. With only weeks remaining until Scotland votes, perhaps those on the Unionist side could do us all a favour and admit as much. All it would take is a little honesty.