It's a measure of the mind of the unionist campaign that it actually thinks "No Thanks" is a more positive slogan than "Better Together."

In the television debate with Alex Salmond, Alistair Darling once again demonstrated that he is the master of the "cannae-dae" mentality.

A finger-waving, scolding Holy Willie. Appalled at the unnatural horror of a First Minister who is not one of the elect, at one point he whined at Salmond: "I never voted for you."

Nevertheless, it can't be denied that Darling caused some damage on the currency issue. Johann Lamont, Scottish politics' very own human battering ram, followed up in the Scottish parliament.

No Thanks has been hammering the Yes side with this issue for the past six months. They're clearly going to give it laldy in the weeks ahead.

Salmond shows no sign of budging on the matter. He says there will be no Plan B. But he's making a big mistake in this formulation. The average voter might struggle with the intricacies of abstruse economic issues, but everybody understands Plan B. They understand it because, in everyday life, everyone has a Plan B.

If it's sunny at the weekend, they'll have a picnic in the park. If it's rainy, Plan B, they'll go to the cinema. If they can afford it next year, they'll go on holiday to Florida. If they can't, Plan B, they'll go 'doon the watter'.

I had tickets for the Commonwealth Games badminton in Glasgow. I'm not acquainted with the sport. But even I know what happens to any player down 5-11 at the interval who hasn't a Plan B.

Salmond may have rationality and common sense on his side when it comes to an independent Scotland retaining sterling. He may also have the support of distinguished economists. This will count for nothing if he continues to assert he doesn't have a Plan B.

By the standards of everyday life, not having a Plan B suggests foolhardiness, possibly a stubborn wilfulness. It's hardly in keeping with the positive, can-do approach of the Yes campaign.

Salmond is much too generous to his opponents. He contends that self-interest and wisdom will prevail in London in the event of a Yes vote. The rest of the UK would suffer too much, he says, without a currency union.

Unfortunately, this won't cut much ice with the voters. Any tenement dweller knows the danger of a neighbour quite happy to mess up and vandalise their shared dwelling. The average Scot is painfully conversant with the idea of 'heidbangers' and 'bampots', only too willing to damage themselves as well as the people and things around them. And we know the harm that can be caused by the 'gawkit' like Miliband, a political Wallace indeed.

Just because the leaders of the unionist parties wear suits and speak politely doesn't make them any less of a threat. Vandals can wear suits. Look at Fred Goodwin. Look at the City of London.

Having pledged so publicly and so vehemently that there will be no currency union in the event of a Yes vote, could these leaders now go back on that? I doubt it. In fact, I think they'd gleefully cause problems for a newly independent Scottish economy - even if it cost them too.

So why not have a Plan B? Salmond says Scotland will never be locked out of a currency union but, if it does happen, Scotland will continue to use sterling anyway. That sounds suspiciously like the outline of a Plan B.

Why not offer a detailed alternative? In the event of the unionist bullies' proposed economic vandalism, Scotland will adopt its own currency, tagged to the pound sterling. If not allowed our fair share of the assets, we will walk away from the liabilities - a saving of £5 billion annually.

This knocks the issue back into the bullies' court. What will their next line of intimidation be?

The well-prepared always have contingency plans. Let's hope that, by the next televised debate, Salmond has them aplenty, B to Z if necessary, to ram into the greetin-faced heads of the No side - or somewhere even more painful.