Alex Salmond has taken part in just four out of a possible 149 Westminster votes since the Holyrood elections, it was revealed yesterday.

The figures were published by the Scottish Conservatives, whose deputy leader Murdo Fraser urged Mr Salmond to resign as MP for Banff and Buchan.

The First Minister, who was elected MSP for the neighbouring Gordon constituency in last May's election, has vowed to stay on as an MP until the next General Election, which may not take place until 2010.

Mr Fraser said yesterday that Mr Salmond's constituents in Banff and Buchan were being "treated with contempt".

He said: "We warned before the elections that if Alex Salmond became the MSP for Gordon then the constituency would be saddled with a part-time MSP, dividing his time between London and Edinburgh.

"The reality is it is his Westminster territory of Banff and Buchan which has suffered."

Mr Fraser added: "Alex Salmond should do the decent thing and resign as an MP.

He would still be left with two jobs to do - a constituency MSP and First Minister of Scotland."

Details of Mr Salmond's voting record were produced by The Public Whip, a website which tracks the performance of MPs.

It shows that since May 8, Mr Salmond has turned up at Westminster to vote on only two days.

On July 25, he took part in three votes on immigration, the machinery of government and home affairs. The other occasion was on November 19, when he voted in favour of the European Communities (Finance) Bill.

The figures also show he missed a number of votes during the Holyrood election campaign.

It is not the first time that Mr Salmond has been criticised over his decision to continue as both an MP and an MSP.

The Liberal Democrats accused him of breaking a pre-election promise to accept only one salary.

However, the First Minister later announced he would be donating the one-third of his Holyrood salary to which he is entitled as a so-called "dual mandate" politician to a special trust fund to help community projects in the north-east of Scotland.

It means that when his First Minister's salary of £76,907 a year is added to his £60,277 Westminster wage, Mr Salmond's total annual income is £137,184.

A spokesman for Mr Salmond yesterday accused the Tories of "scraping the bottom of the barrel" and ignoring the Scottish national interest.

"There is a clear advantage to Scotland in having a First Minister who can make key interventions at Westminster on Scotland's behalf," the spokesman said.

"For example, on the UK Government's legislative programme or, for that matter, his exchanges with the Prime Minister on co-operating against terrorism."

He added: "There is much more to being an MP than trooping the lobbies at Westminster, as is shown in the latest available league table for MPs' participation.

"Encompassing speeches in the chamber, tabling of motions and submitting written and oral questions, the analysis shows all six SNP MPs, including Mr Salmond, are in the top 10 of Scottish MPs."