I wonder if Tommy Sheridan ever gets fed up of being called a ‘firebrand Scottish politician’? Probably not, any more than the far more loathsome George Galloway tires of presenting himself as the victim of conspiracy theories, the latest of which is so tiresome I could not get beyond the first eight sentences of The Guardian report.

Sheridan, with whom I crossed swords many years ago when we were changing a Labour Party constitution all but a handful still believed in, is a warmer and more attractive firebrand that not-so-gorgeous George. So when I sat opposite him on the This Week sofa last night, watching the film he had made claiming the independence campaign would be won, I found I was smiling more than I expected to, because reminds me of a more politicised version of that shouty guy with hair who does programmes on coasts, and lots of voiceovers.

In retrospect, he may think it was an error to end his film by lifting his kilt to reveal a picture of Andrew Neil where his privates woud normally be, before immediately saying he hoped there would be a serious and mature debate!

But more seriously, much as I enjoyed our little discussion, I feel he opened up what will become a huge faultline in the Yes Scotland campaign, a faultline which rests on this question: ‘Whose version of an Independent Scotland are we voting for?’

Of course it is now an unofficial part of the unwritten Constitution that whenever you mention SNP leader Alex Salmond, you have to preface with the word ‘canny’, or state, as Michael Portillo did last night, that he is ‘not to be underestimated’. Well, certainly the support he won at the last Holyrood elections would suggest so. However, I am not convinced that the alleged canniness will be borne out by the decision to have such a long campaign. Because the difficult questions are beginning, and the answers are becoming more and more confusing.

Tommy was upfront about the fact that the referendum will not settle any questions about what kind of Scotland an independent Scotland would be. The direction and policies are all to be resolved afterwards, he said. And he was clear that he was backing the campaign because he saw it as the route to higher taxes, the end of the Queen’s rule, farewell to Trident, and to NATO, and hello to an independent Scottish currency.

But Salmond knows that just as Sheridan could never win a majority for that approach in the Labour Party when he was part of it, he has absolutely no chance with the country as a whole. So Salmond is promising that the Queen stays, the hated Bank of England continues to be a force in the land, and Scotland will remain a big player at the UN, NATO and in the UN (overlooking the fact he may have less of a say in all that than he thinks.)

And meanwhile, as I said last night, there are right wing Scottish businessmen saying an independent Scotland can become a Swiss like tax haven – hardly the kind of socialist utopia Tommy Sheridan believes in, or the kind of socially progressive land Salmond claims to support.

So whether it is Big Eck, Tommy, the Greens or the few Tory businessmen saying Yes, the problem is that when you ask them any serious questions about which vision of Independence you are actually getting you are told that you have to wait until after you have voted for independence. I am not sure that is the best strategy for winning over waverers, who tend to look for greater certainty than those who already think they know their minds.

Independence has this week gone from something imaginary that Salmond and Co could give glib answers on,
or which could be used as a way of talking about every grievance caused by ‘London rule’, to
something which people know they are going to have to make a permanent and important decision on.

Rainbow coalitions have a habit of looking pretty as they take shape, them getting ugly as the constituent parts realise they really are of different colours, and can’t coexist without causing division, confusion and, when characters like Sheridan and Salmond are around, rancour. That is when Alistair Darling’s cool, calm, detail-driven, allegedly non-charismatic style will come into its own.