The Scottish National Party is marking the first anniversary of its election to power today, as it hits 45% in an opinion poll - its highest-ever rating and a stunning 14 points ahead of Labour.

The Scottish National Party is marking the first anniversary of its election to power today, as it hits 45% in an opinion poll - its highest-ever rating and a stunning 14 points ahead of Labour.

But that support level, for the Holyrood constituency vote, is not matched by Scots' intentions for the next Westminster election where Labour's support is holding up - at 39%, it is eight points ahead of the SNP.

The findings, from a TNS System Three survey of 1086 voters from April 26 to 29, showed Westminster voting intentions registered 17% for Conservatives, far below the 44% secured yesterday in council elections in England and Wales. LibDems were on a poor 10%, less than half of their Westminster turnout at the 2005 ballot.

The Holyrood picture was different from Westminster, where First Minister Alex Salmond has set his party a target of gaining 14 seats out of 59, on top of the six it holds. The poll showed the SNP on 45% of the constituency vote, with Labour on 31%, Tories on 12% and LibDems on 11%.

On the regional list vote, the SNP lead was almost as comfortable, at 41% and 12 points ahead of Labour, while Tories and LibDems were each on 12%. The Greens attracted 4%; Socialists and Solidarity polled only 1%.

Another poll, by YouGov published earlier this week, registered 36% support for the SNP on the Holyrood constituency vote, with Labour on 31%, LibDems on 15% and Tories on 13%. On the regional vote, YouGov's internet sample showed the SNP on 37%, Labour on 28%, LibDems and Tories on 13%. For Westminster intentions, Labour had 34%, four points ahead of the SNP, with Tories on 17% and LibDems on 14%. The latest rating is a boost for the SNP as it marks a year since its election breakthrough. Only once since the advent of devolution have Nationalists registered above 40%. In September 2000, following their national conference, they peaked at 42% before slipping back. At last year's Holyrood election, Labour won 33% of the constituency votes and 31% of regional ballots.

SNP deputy leader Nicola Sturgeon said: "A year after the historic elections, and as Labour disintegrates, the growing SNP lead shows that the honeymoon continues on the back of solid policy delivery."

Chris Eynon of System Three said: "At 45%, support on the constituency vote matches the highest achieved by Labour at their peak on only one occasion in five years of monthly System Three polls for The Herald from 1999 to 2003, and it exceeds anything recorded by the SNP over the period.

"The fact Labour support is holding up on the Westminster vote is interesting in highlighting the number of potential Labour voters switching their allegiance, either disaffected by Labour's poor showing in Scotland or won over by the SNP performance."