Scotland's opposition parties have yet to get the hang of Alex Salmond. This, I concede, is not news. When the First Minister can be heard trumpeting opinion poll results - albeit results from surveys commissioned by the SNP - you could be forgiven for forgetting that this is the leader of a minority administration with the slimmest of parliamentary advantages. Mr Salmond sounds like a man grinding opponents into the dust, and loving every minute of it.

Labour, in particular, still shows every symptom of post-traumatic stress. The tale of a dodgy donation has come like a standing count to a fighter on the ropes. The party has been shocked rigid by the loss of power and its response has been a mixture of defiance, denial and incoherence. It has a century's stock of platitudes at its disposal - best summarised as "the People et cetera" - but no ready answer to an ancient question.

What is to be done? Search me (or my office), say Labour folk. Their problems could be mistaken for a parochial echo of Gordon Brown's difficulties - a checklist of missing items, from a sense of direction to decisiveness - but actually go much deeper. The plight of Scottish Labour, the erstwhile "old" Labour, feels like a foretaste of the judgment awaiting the Blair-Brown project. The cupboard is bare, the tank is empty. Things can only get sticky.

Doing nothing is not an option. Wendy Alexander, to her credit, has not flinched from saying as much. The risk of Mr Salmond turning a small electoral win into triumph by default is great. His incrementalist strategy was paying off long before a cheque for £950 was added to Labour's bill. If there is no response - and I do not exaggerate by much - the natural party of Scottish government is finished, and the Union with it.

Hence one sweet and savoury irony. The Labour people who told us not so long ago that voters, the ones forever manning "the doorstep", are bored with constitutional navel-gazing have changed their tune. Suddenly the home rule settlement is the favourite destination for a return visit. "Upheaval", once the preserve of the obsessive and irresponsible, is respectable. It is intended - and here's where both fun and confusion begin - to do for Mr Salmond.

Ms Alexander and her party have allies ready and waiting. The Tories and the Liberals also need to find a way to counter the SNP, or at least to assert their own continuing relevance. The singular product of the recent Scottish elections was less a Nationalist administration than a grand, if informal, Unionist coalition. Mr Salmond offers them his "national conversation"; they talk of alternatives, of another, still another, constitutional convention. Or "commission" - invitation only but publicly-funded, if you prefer.

Two enticing questions arise from the proposition. The first is brutally simple: is there, in fact, an alternative? Is there a way to conceive of Scotland's future that avoids Union-or-bust, independence or status quo? The very fact that Labour, Tories and LibDems are making common cause, adopting agreed strategies and involving their Westminster MPs in the discussions might suggest the battle lines are already drawn. How do you define parliamentary opposition in Scotland? Simple: whatever is non-Nationalist.

But there's your second question. Wouldn't a sensible dyed-in-the-wool Unionist recoil from any and every sort of revived constitutional convention? Didn't that affair simply inaugurate the process that saw Mr Salmond take power? Doesn't it just feed the Nationalist beast? Once you start, where do you stop? Isn't a convention/commission mere appeasement?

Ostensibly, the topic for which Labour and its allies secured a parliamentary vote involves more powers for Holyrood. Polls suggest this ill-defined idea is popular. If you pore over such snapshots, therefore, and if you practise only political short-termism, you might detect a no-brainer. A majority does not want independence. A majority does want to see more legislative muscle in Edinburgh. What better guarantee of popularity than giving the people what the people want? It's almost an obligation. The master plan overlooks a detail, however. What does Mr Salmond want? Nationalists have been busy scorning the schemes of the new triumvirate, but those protestations should not be taken too seriously. Even while they advertise the superiority of the national conversation over other talking shops, the SNP probably cannot believe its luck. What's the only phrase ever to matter in politics, and Nationalist politics in particular? "More power".

A commission that would, in the terms of this week's motion, "enable the Scottish Parliament to better serve the people of Scotland, that would improve the financial accountability of the Scottish Parliament and that would continue to secure the position of Scotland within the United Kingdom" is something with which Mr Salmond can live. It is, I suggest, something he can revel in.

Think of the scope for constructive suggestions. Think of the opportunities to point out, with a gentle grin, that those who acknowledge deficiencies in the Union are merely advertising the merits of independence. The LibDems can at least promote the coherent claims of federalism. The Tories have to hack their way through the backwoods of Little England sentiment. Labour has to explain what Ms Alexander thinks she's playing at.

"Improve the financial accountability of the Scottish Parliament"? Are we truly talking about money? If we are not talking about money, we are not talking seriously. Yet if fiscal autonomy, even limited autonomy, is the name of this game both Mr Salmond and his Finance Secretary, John Swinney, will be keen to play. Why on earth not? They would be playing, as it were, at home.

Not for the first time or the last, I refer you to an important distinction made by Tom Nairn, the ground-breaking scholar of Nationalism. As Mr Nairn has pointed out, any nation can aspire to de jure independence, with flags, banners, embassies and solemn treaties. But de facto independence, independence to all intents and purposes, independence achieved without fuss, almost unnoticed, can be just as valid, certainly just as real.

Mr Salmond already wishes to retain the monarchy and Commonwealth membership under a kind of independence-in-Britain. Not my preference, but never mind. The Unionist parties, meanwhile, seem to be bent on meeting him halfway just by raising the possibility of increased autonomy. And they do not appear to have an inkling of what they are doing.

Fine by me. My kilt never made it back from the cleaners, so I only ever ask two questions. Are identifiable nations entitled to self-determination? Is the Union, cultural, political and economic, an impediment to Scotland? The rest I leave to those who fancy careers in diplomacy or the oil business.

It seems clear, nevertheless, that Scottish Labour is paying the price for London's lapsed concentration. Labour at Westminster, Tony Blair above all, didn't think this through. They told themselves that devolution would fix the SNP once and for all. It did nothing of the kind. In fact, it did the opposite.

These are very early days, but as things stand Mr Salmond's chances of improving his parliamentary position at the next Scottish elections seem excellent. Now Labour wants to enhance the status of the forum he has made his own. "Brilliant" isn't the word. The Christmas turkey vote is in early.