THE SNP's 56 MPs are an "impotent" force at Westminster who hold less influence collectively that one Treasury minister, one of the most high-profile casualties of May's nationalist landslide has claimed.

Danny Alexander, the former Highland LibDem MP who served as Chief Secretary of the Treasury in the last government, lost his seat in to the SNP's Drew Hendry by a margin of more than 10,000 votes despite claiming to have used his position of power to deliver for constituents in the north.

Speaking ahead of the budget, he raised concern over the absence of a Scottish MP in the Treasury for the first time since devolution.

He said: "In the end what you have is Scottish nationalists in Scotland totally impotent in terms of what happens in the UK. I think Scotland in a way has less say over what happens in this country without one minister in the Treasury even though it's got 56 SNP MPs."

Mr Alexander also claimed that the Tory tactic during the general election campaign of warning of the SNP holding a Labour government to ransom had contributed to his party's UK wipeout. The LibDems saw their number of seats reduce from 56 to just eight in May, and were replaced by the SNP as the third largest party at Westminster.

He added: "I still felt that actually our support being concentrated in a lot of our constituencies that we could hold enough seats in the election to come through and potentially play another role in government.

"I think the reason that we didn't do that was because the Conservatives very effectively played this tactical squeeze message that said that if they didn't have a Conservative majority that people who just six months before tried to break the United Kingdom would then be allowed through the back door to govern it.

"Voters in England to an extent that I didn't recognise during the campaign really resented the idea."