A prize leak in Caledonia: LEADING ARTICLE

Battle has been joined for who is to wear the glorious mantle of that Scots brave heart Mel Gibson, er, sorry, William Wallace. Will it be baby-faced Alex Salmond, leader of the Scottish National Party, whose conference opened in Perth yesterday? Or will it be the avian George Robertson, Labour's shadow Secretary of State for Scotland?

Currently nearly twice as many Scots prefer Mr Robertson's plans for a devolved Scottish parliament to Mr Salmond's scheme for full independence. But in spite of this the SNP is on something of a high, reflecting increased Scots national self-confidence; the last by-election in Scotland, Perth and Kinross, was a triumph for the Scot Nats' candidate. This result has heightened the sense that the debate about full independence is only just beginning. Labour, therefore, has reason to be nervous.

How convenient, then, that on the morning that the Nats were due to begin their conferring, a "leak" of an internal Labour document in the Scotsman should propel Mr Robertson into the radio and television studios of Caledonia to talk about the "darker side of nationalism".

And what strangely external language this internal memo is couched in. Supposedly addressing colleagues (who, one might have imagined could be presumed to know the same things as Mr Robertson), the Labour man tells a tale of tartan extremism, fostered by the ostensibly respectable SNP. The party's leaders are "fuelling a crazy fringe", who in turn have threatened the lives of prominent anti-independence Scots. He accuses the SNP (in his letter to his own colleagues, remember) of standing back from the extremists, while sustaining them with rhetoric and prejudices.

There are two issues here: the first is simply to note this rather crude version of the old technique of spoiling other people's conferences for them. It is hardly news, however, that new Labour has now surpassed Conservative Central Office in its application of these political black arts.

The second is a wee bit more serious. It is certainly the case that there is a lunatic nationalist fringe in Scotland. This fringe is tiny and unimportant. It is also true that low-ranking SNP officials will occasionally describe Labour Party folk unflatteringly as "Uncle Toms" or traitors to the nationalist cause. They should be rebuked by their leaders for so doing.

But the effective characterisation by Mr Robertson of the SNP leadership as Slobodan Salmond and his Tartan Tigers does a disservice to the debate about Scottish independence. Whatever one's views in that debate it is surely true that the SNP has prosecuted its case in an entirely constitutional and legal fashion. Indeed, what is surprising about Scotland's recent history is not how much passion the issue of separation has raised, but how reasoned has been the conversation.

As we move into a period in which the question of Scotland's constitutional status is likely to be of great importance in British politics, Mr Blair must insist that his lieutenants contribute positively to achieving the right outcome, rather than diverting discussion down the arid alleys of name-calling and abuse.