His forecast of a thrilling contest was made yesterday at the official launch of the SNP campaign.

However, the First Minister stopped short of predicting a win for his candidate, David Kerr, saying there was an advantage in entering the campaign as underdogs.

He said: "We are expecting a brammer of a by-election with a monster result for the people of Glasgow North East and the people of Scotland.

"People know for the first time there is a chance of an SNP win but I think it’s a better position, on reflection, not to boast that we will win but just to say that we can win, if the people so choose."

Mr Salmond’s low-key approach was in contrast to his bullish outlook at the Glasgow East by-election last year, when he accurately forecast a "political earthquake" with the SNP taking the seat from Labour.

Mr Kerr took the opportunity to apologise for a comment he made two years ago, when he said Glasgow Caledonian University "did not have a reputation to tarnish".

He said it was made "in jest", adding: "If anybody was offended, no offence was intended and I’m sorry."

The launch of Mr Kerr’s campaign took place on the eve of the SNP’s annual conference, which starts in Inverness today. Delegates will discuss resolutions on the recession, the economy and the renewal of Trident submarines, which Mr Salmond said was the "worst job-creation exercise" there had ever been.

He added: "Here’s a deal for the Labour Party. They cancel Trident, give us the capital and we’ll go ahead with Garl [Glasgow Airport Rail Link] and many other capital schemes I’d like to see."

The bookmakers’ favourite to win the seat is Labour’s Willie Bain, who launches his campaign on Monday.