It is not unusual for the Scottish National Party (SNP) to have an opinion poll lead north of the Border five months before an election. It is unprecedented for it to be in that position a mere five weeks before the ballot boxes are opened. Yet this is, the Populus/ Times survey today indicates, precisely the situation. Alex Salmond and his supporters are on course to win both the most votes and the largest number of seats in Scotland on May 3. If that were to occur, the implications for all British politics would be considerable. The SNP would have a real chance of implementing its pledge to hold a referendum on independence within the next three years.

There are, of course, caveats here. This same poll shows that, while there is public backing for the Scottish Parliament to assume additional powers, the appetite for an outright divorce from the rest of the United Kingdom is limited. The voters appear to have become disillusioned with Labour under the leadership of Jack McConnell, the First Minister, far more than they have been seduced by the SNP. The electoral system in this contest, furthermore, is proportional. While the SNP would, on this evidence, claim more MSPs than Labour, it would come nowhere close to a majority. It would require coalition partners to form an administration and these would be in short supply. The Liberal Democrats, for example, who will probably secure the role of kingmakers, do not want to share office with Mr Salmond if he insists on a vote over independence.

Labour cannot afford, though, to rest on its laurels. If the SNP does as well as seems likely, it will be the moral victor in this election, even if it is denied power. The only alternatives to it would either be a “traffic light” combination of red, yellow and green (Labour, the Lib Dems and the small Green Party), or a minority Labour-Lib Dem coalition sustained by the tacit backing of the Conservatives. In either case, the Cabinet that emerged would be weak and Mr Salmond could contend with some credibility that the old parties had conspired to keep him out and deny Scots a vote on independence. He would then be well placed for the 2011 Scottish election.

Labour should therefore be seeking to win this election by the front door rather than relying on what would now be doubtless smoke-free rooms in which to strike a bargain with other parties. It has to be a lot more attractive to the electorate than it has been. This involves admitting that it is less the authority awarded to the Scottish Parliament that is the problem than that Labour itself has been too unimaginative with the power it possesses already. Scotland essentially has endured an old Labour government which has been too inclined to look to the State for salvation. Scottish Labour’s troubles are less Tony Blair than the absence of Blairism.

This race will become closer as polling day approaches. Most Scots appreciate that Mr Salmond is, for all his charisma, untested at the highest level and that the SNP as a whole is a very left-wing party which is even less inclined than Labour to undertake sweeping reforms. It will not be enough, nevertheless, for Labour to bash the SNP as a vote for the unknown and hope to scare Scotland into rejecting it. It is hard to contend that a democratic ballot on independence is an outrageous suggestion. Labour, as the natural party of government in Scotland, has yet to make a case for itself which is compelling. At the moment, it is hard to envisage what such an argument would be.