LABOUR'S GRIP on Scotland appeared to be slipping away last night after a new superpoll found the party was set to lose an election in the country for the first time in half a century.

The new YouGov survey, which is the biggest sample of opinion taken since the campaign began, found the SNP to be 8% ahead of Labour in constituencies and 5% ahead in the regional list vote.

The 10% swing from Labour to the Nationalists since 2003 would install Alex Salmond as first minister and unseat some of Labour's most senior MSPs, including health minister Andy Kerr.

It also comes four days before Scotland goes to the polls in what is widely recognised as the country's most important election for decades.

The YouGov poll, which was sponsored by the Economic and Social Research Council, makes grim reading for first minister Jack McConnell as he tries to hold on to power, but it will delight the Nationalists, who are on the verge of winning power for the first time in their history.

It has put the Nationalists on 38% of the constituency vote, eight ahead of Labour, with the LibDems trailing on 15% and the Scottish Conservatives in fourth on 12%.

On the regional list vote, the SNP's support was found to be 32%, five points ahead of Labour, with the Tories on 14% and the LibDems fourth on 12%.

A seat projection based on the poll results gives the SNP 47 MSPs, up by around 20 from the 2003 election, with Labour on 40, down 20% from four years ago. The LibDems and Conservatives would each get 18 seats, with the Greens getting five and the SSP one. Such a result would give the Nationalists and LibDems the narrowest of majorities to form a coalition.

The result, which if replicated on Thursday would end Jack McConnell's political career, would also result in many of his colleagues losing their seats.

A 10% swing would be enough to help the SNP win 18 first-past-the-post seats from Labour, as well as several other berths from the LibDems and the Conservatives.

In particular, the projection would see the Nationalists unseat health minister Andy Kerr in East Kilbride and former enterprise minister Wendy Alexander in Paisley North.

It would also spell the end for Labour's education minister Hugh Henry in neighbouring Paisley South, deputy communities minister Des McNulty in Clydebank and Milngavie, and deputy enterprise minister Allan Wilson in Cunninghame North.

The YouGov poll is significant as it was based on canvassing the opinion of over 1800 voters, by far the biggest snapshot of the campaign.

It is also similar to the last YouGov poll, which found a nine-point lead for the Nationalists on the constitu-ency vote.

The SNP's momentum has received another boost after several high-profile artists added their names to a newspaper advertisement that endorsed the SNP. Author Christopher Brookmyre, artist Peter Howson and indie band Mogwai have all climbed aboard the Nationalist bandwagon.

The problems facing McConnell and the Labour campaign are also set to worsen following an interview with chancellor Gordon Brown today on the Sunday Edition TV programme, in which he appeared to downplay the importance of the Holyrood election. He said: "Look, the only result that matters in the end is when it actually comes to a general election and people decide what they want to do."

SNP campaign director Angus Robertson said: "We are absolutely delighted with this poll - the largest sample of any poll during the campaign. It gives the SNP a commanding lead of 8 points on the constituency vote and 5 points on the list vote.

"The SNP's positive campaign is in lift-off as we enter the last few days," he added.

A spokesman for the Labour Party said: "The poll is a clear message to voters that they face a real choice on Thursday. If people want a strong and stable economy, with more jobs and investment for schools and hospitals they should vote Labour, or the SNP alternative of high tax, turmoil, instability, cost and risk."