The SNP has highlighted new figures indicating that its MPs have contributed to more parliamentary debates than members of other parties.

Figures from the House of Commons library, covering the 12 months to November 2003, showed that on average each of the five SNP MPs made a total of 46 contributions to debates in the chamber.

This was the largest out of all the political groups in the Commons and over double the average of 20 debate contributions per MP.

On average, Liberal Democrat MPs made 29 debate contributions, the Tories 28 and Labour backbenchers 29.  If government ministers are included, the Labour figure declines to 16.

Alex Salmond, Angus Robertson, Mike Weir, Pete Wishart and Annabelle Ewing said in a joint statement that they were speaking up for Scottish interests.

"By contrast, Labour MPs and those from the other London-based parties regularly stay away from debates, or don’t say a word even when they do turn up – and then troop through the lobby to vote against Scotland’s interests," they added.

"For example, during the recent debate on university top-up fees, there were no Scottish Labour MPs present in the chamber – with the honourable exception of Tam Dalyell, who voted against the government.

"But they turned up at the end to vote for top-up fees in England, which will create a funding shortfall for Scottish higher education.

"Scotland needs MPs who speak for Scotland and vote for Scotland – a job that only the SNP are able and willing to do."