Imagine an independent Scotland without the SNP.

Today Alex Salmond and his party are such a dominating force in the nation's political life that it is difficult to envisage a future without them. However, the man doing the imagining is none other than Stephen Noon, who has worked for Mr Salmond for close on two decades and is currently chief strategist of the Yes Scotland campaign.

The idea is less fanciful than it may seem. Four decades ago it was a widely held view among Scottish nationalists that the SNP would cease to exist following independence, its sole common objective having been realised. During the 1970s, former SNP chairman William Wolfe is reported to have said that upon independence the party would immediately disband.

Writing in a Sunday newspaper, Mr Noon suggests that once the constitutional question is disposed of, political meltdown could ensue and many traditional party divisions disappear, ushering in an era of political promiscuity for voters and some surprising political bedfellows. A nationalist Labour coalition? Why not, even if Mr Noon admits that such a prospect will have many party supporters "spluttering into their porridge"?

What are his motives in suggesting such a scenario? Given his own political affiliation and present job description, the answer must be that he believes it will make Scottish voters more likely to say yes to independence. It is very much in the interests of a political strategist to get everyone, including his opponents, talking as if what he is trying to bring about is a fait accompli. The more voters he can persuade to refer to an independent Scotland in the future tense ("will"), as opposed to the future conditional ("would be"), the more he has to gain. Also, in a year that has seen trust in traditional party politics and politicians in general badly eroded, the prospect of what he calls "a real opportunity for a fresh start in Scottish politics and for Scotland" holds a certain appeal. The SNP hierarchy may have too much to lose for the sort of spontaneous combustion envisaged by Wolfe. Nevertheless, if the political gravitational pull of independence were to be removed, who knows what centrifugal forces would surface, especially between the social democratic anti-poverty wing and the pro-business, small-state, low-tax wing of the party, which have little in common. The campaign's narrative may be that a prosperous independent Scotland will be able to afford to tackle the nation's huge inequalities in health, education and income distribution but major disagreements about ways and means and short-term priorities could tear the party apart in the meantime.

Whether, under such circumstances, Scotland would be better off within or outwith the UK is a moot point. Much may depend on whether the Conservatives or Labour look more likely to lead the next Westminster government.

The question Mr Noon fails to tackle is what will happen to the SNP if Scotland rejects independence. Is a similar fragmentation a distinct possibility?

Rather than speculating about the future of the SNP, the Yes campaign first needs to persuade voters that an independent Scotland would be more prosperous and more fair. It has yet to make that case convincingly. Until it does, a majority of voters are likely to continue to regard independence as a leap into an uncertain future rather than a fresh start.