Constitutional Alamo is premature fantasy

If the Prime Minister's official spokesman needed any excuse for his oft-repeated view that a hostile - and now ''ridiculous'' - Scottish media is at the root of New Labour's travails north of the Border, Alistair Campbell will have found reinforcement in abundance in the welter of apocalyptic comment which has appeared elsewhere following our latest poll finding that the SNP is five points ahead of Labour in voting intentions for the Scottish Parliament.

Don't get me wrong. I believe the trend which we and System Three have unearthed in recent months is highly significant and is sending the Government a telling message about the present mood in Scotland, one it seems extremely reluctant to absorb. But the idea that Scotland's Unionist parties, including New Labour, are all now embarked on a one-way train to some constitutional Alamo is premature fantasy. The most recent evidence on popular support for Scottish independence, in last weekend's ICM poll for Scotland on Sunday, showed 33% of the sample favouring the SNP's ultimate ambition against 48% still backing devolution.

Alex Salmond and his colleagues have yet to prove - to themselves as much as to the rest of us - that the groundswell of support for SNP candidates for the Holyrood Parliament, now being registered month-by-month in our own poll, equates to an embryonic mandate for Scottish independence.

There may be an element of that. The 33% score for independence in the ICM poll was five points up on the level detected in the same poll in February. But support for devolution was steady, at 48%. It is backing for the No Parliament position which has been eroding, down from 21% to 17%.

In the world of realpolitik, with Donald Dewar and his team now accelerating the timetable for the Holyrood Parliament to take full responsibility for its devolved powers, those Scots who want to turn the constitutional clock back will eventually have to choose. While some die-hard No:No Unionists may prefer the clean break independence offers - remember the Allan Stewart position? - it is inconceivable that most of that dwindling No Parliament segment of opinion will follow suit.

Most are much more likely to opt, reluctantly, for making the Holyrood Parliament Labour is delivering work.

The challenge facing the SNP will be to go on converting the margins of established devolutionist opinion to the cause of independence. How should it go about that task? Suppose the trends the Herald/System Three polls have identified continue. We are in complex and virgin electoral territory here, territory that politicians, voters, pollsters, and media commentators are all struggling to assess and understand. But suppose current polling trends continue and the SNP emerges next May as the largest single party in the Holyrood Parliament. What should a party whose core aim is Scottish independence do then to win over

the majority of Scottish opinion to

its cause?

Much would depend on whether the Nationalists had an overall majority. Given the uneven distribution of the core support from which the SNP seeks to build, that still seems unlikely. All Scottish voters will have two votes next May, one for a first-past-the-post candidate and another which will only count proportionately in a regional list. We do not know how many voters will switch these two votes around different parties, but there is now opinion polling evidence that some will.

Let's imagine, on the basis of the provisional wisdom currently available to us, that the SNP emerges as the largest single party, but short of an overall majority. It could try to mount an immediate referendum on independence, something Alex Salmond has hinted at in the past. Such a proposal would enrage all the Unionist parties ranged against it. And if they collectively had more MSPs, it's hard to see how the SNP could force it through.

An early referendum would also cause a constitutional fracas with London, given that the constitution of the United Kingdom is, under the Scotland Bill, a matter reserved to Westminster. But if the SNP had just trumped Labour in the first elections to the Parliament Labour had so assiduously delivered, the Nationalists might try to claim the moral authority of such a devastating victory.

Like Strathclyde region on the issue of water privatisation, a minority SNP government in Edinburgh might still run an independence referendum whatever constitutional lawyers said. But no dominant SNP group at Holyrood would be daft enough to run that referendum unless it was certain of winning it.

And that brings us back to current realities. Independence is still the preferred constitutional option of only a third of Scots, a level it has reached several times in recent decades. To turn that third into a referendum majority, a dominant SNP group in Holyrood would have two broad strategic options.

It could try to use the new Parliament as a focus for national discontent, constantly criticising London parsimony and London rule on the issues over which it had no control. That seems to me the higher risk option, one that risks alienating a public which has invested the Holyrood Parliament with high, even unrealistic, hopes.

The smarter option would be for the SNP to use its new-found power constructively, to demonstrate that the SNP can - in chief executive Mike Russell's words of Wednesday - ''govern well'' and, by governing well, ''seek to give the people confidence so that they will want to go further''.

Put another way, were the SNP to vindicate this week's poll findings in the real Scottish Parliament elections a year from now, they might well find themselves forced to make Labour's devolved legislature work, before

they could hope to win a majority mandate for full independence. Away from intoxicating talk of last stands for Unionists, we may really be talking about an indefinite apprenticeship for Nationalists.