PRESSURE is mounting on Ed Miliband and Labour in the run-up to the General Election as a new poll predicted the party faces a wipe-out in Scotland.

The Labour leader's bid to become Prime Minister has been further damaged by Conservative peer Lord Ashcroft's latest poll, in which voters were questioned about their intentions in 16 of 59 Scottish constituencies.

The survey suggested the party could be facing the loss of its Glasgow stronghold to the SNP and a meltdown across Scotland on May 7.

The poll includes 14 Labour and two Liberal Democrat seats that voted Yes in last September's independence referendum or where the result was close. It showed all but one would be swept up by the continuing Nationalist surge.

But senior Labour sources hit back saying David Cameron's "last best hope" of staying in power rests with Scotland splitting the centre left vote.

Some of the party's most senior politicians, such as frontbenchers Margaret Curran and Douglas Alexander, Labour's election campaign manager, would lose their seats to the SNP if the numbers were repeated at the election.

Former First Minister Alex Salmond would easily win the Aberdeenshire seat of Gordon, while Liberal Democrat Treasury Chief Secretary Danny Alexander would lose Inverness, Nairn, Badenoch and Strathspey.

Nationalist insiders, buoyed by the latest survey of 16,000 Scots, indicated there was now a "decapitation" policy to oust the Cabinet minister from his Highland powerbase.

Scottish Labour leader Jim Murphy acknowledged recent polls were bad for his party but expressed confidence they would change. One poll earlier in the week gave the SNP 48 per cent and Labour 27 per cent.

"Polls will close late," he declared. "I don't think we'll close six to 10 per cent in a week; it will be a determined effort on polling day.

"These numbers will switch during the campaign when they see the contrast between the two candidates. These TV debates, although they are crowded now and seem more like an episode of Fifteen To One than they do a debate among the characters who are going to be PM. But when they go head to head in these debates people will see the authenticity of Ed Miliband, the changes he wants to make versus the smooth but superficial thing David Cameron offers."

Earlier, a source close to Mr Miliband said: "What people need to realise is that for every one Labour MP lost in Scotland, there is a direct increase in the chances of a Tory government."

He added: "The election is going to be won and lost across the country but there's no doubt part of the Tory tactic at the moment is to think they can get away with splitting the centre left vote in Scotland and scraping home on that. That's their last best hope."

The Ashcroft poll showed the overall swing to the Nationalists in Labour-held constituencies was more than 25 per cent. If repeated nationally, the party would lose all but six of its 41 Scottish seats. The survey looked at all seven of Labour's Glasgow constituencies and found the party would retain one; the city's North East seat.

In the 14 Labour-held constituencies polled, 60 per cent of those who voted Labour in 2010 said they would do so again this year; some 35 per cent said they would switch to the SNP.

While the Tory vote held up well in the polled seats, the Liberal Democrats' collapsed; only 12 per cent of the party's 2010 supporters said they would vote Lib Dem again; 47 per cent said they would switch to the SNP.

The single most popular election outcome was a Lab-SNP "coalition".

Angus Robertson, the Nationalists' election campaign chief, said: "These polls include some of Labour's safest seats in the whole of the UK as well as Scotland and they are clearly excellent for the SNP. But we are taking nothing for granted and will work hard for every vote."

Ruth Davidson, the Scottish Conservative leader said the snapshot confirmed Mr Miliband was not trusted by Scots and the LibDems had collapsed as

a political force in Scotland.: "Both those facts make one thing clear; the only pro-UK party with the strength and leadership to challenge the Nationalists is the Scottish Conservative Party."