The SNP are set to decapitate Scottish Labour at the general election with the nationalists polling ahead of Jim Murphy in his marginal seat.

A survey from Lord Ashcroft, which questioned more than 1,000 voters in East-Renfrewshire, found that there has been a 26.5% swing from Labour to Nicola Sturgeon's party in the constituency since 2010.

The study, conducted between 11 and 16 April, also found that the SNP have a nine-point lead over Labour in the seat (31% vs 40%).

Ashcroft said: "This seat has a bigger Conservative share than many other Labour strongholds (25%) and I found Conservative voters less likely to say they would rule out voting Labour (64%) than would rule out the SNP (87%). How many Tories will decide to lend their vote to Jim Murphy to stop the nationalists?"

Murphy, however, does have an advantage: name value. Ashcroft's questionnaire did not specifically name the candidates on the 7 May ballot sheet.

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But the researchers did ask: "And thinking specifically about your own parliamentary constituency at the next general election and the candidates who are likely to stand for election to Westminster there, which party's candidate do you think you will vote for in your own constituency?"

Scottish Labour will also hope to keep the seat by winning the so-called "ground war" between campaigners as Ashcroft's data showed their contact levels were 12 points higher than the SNP in the seat (78% vs 66%).

Murphy won East-Renfrewshire in 2010 with a majority of more than 10,000 and more than 50% of the vote. He became Scottish Labour leader in December last year, replacing Johann Lamont.

Elsewhere, equalities minister Jo Swinson, who has a majority of just 2,184, is set to lose East Dunbartonshire to the SNP as the senior Liberal Democrat is 11% points behind the insurgent nationalists.

She admitted to IBTimes UK earlier in the year that the election was "going to be a challenge".

The research also revealed that the SNP had extended their lead in the polls in Douglas Alexander's constituency of Paisley and Renfrewshire South to 11%, up from 8% in February.

The Labour shadow foreign secretary is facing a 26.5% swing against him since 2010, when he secured a 16,614 majority.