Scottish Labour leader Jim Murphy has warned that Scotland would be "turbo-charged towards a second referendum" if more than half of Scots vote for the SNP next week.

A Survation poll for the Daily Record today found 51% of Scots plan to vote for SNP candidates in the General Election on May 7, leading to the party winning 55 of Scotland's 59 seats.

The poll has Scottish Labour support at 26%, the Tories on 14% and the Liberal Democrats on 5%.

Mr Murphy conceded it was a bad poll for Labour and said it was a "fantastic" poll for the Tories, describing Prime Minister David Cameron as a "cheerleader-in-chief" for the SNP.

He called on voters to back Labour for a road to a fairer Scotland rather than a second referendum with the SNP.

He said: "We've confounded the polls before, we've been the underdogs before and we've turned them around.

"I'm confident that we can make a big inroad into these polls and every seat that Labour wins here in Scotland is a seat closer and a step closer to David Cameron being out of office, and a step closer to having a Labour government.

"But we want a Labour government that does things differently. We don't want a return to the Tory austerity and we don't want a rerun of the SNP's referendum which, if this poll is borne out on election day, Scotland would be turbo-charged towards a second referendum, and that's not what we need."

He added: "It's another bad poll for the Scottish Labour Party, it's a good poll for the SNP and it's a fantastic poll for David Cameron because David Cameron can't win seats in Scotland, he has to get someone else to beat the Labour Party for him and in this election David Cameron has turned into the cheerleader-in-chief for the SNP.

"We can spend the next few years trying to re-run the referendum debate with the SNP or we can spend the next few years trying to rebuild Scotland's NHS and build 100,000 high-quality family homes here in Scotland.

"That's a better and a fairer way of spending the next few years rather than returning to last year's divisions."

The Scottish Labour leader was on the campaign trail in the east end of Glasgow today along with shadow energy secretary Caroline Flint and Scottish Secretary Margaret Curran.

They visited a building site in the Tollcross area where Parkhead Housing Association is building homes.

Mr Murphy said Labour would build 100,000 new high-quality family homes across Scotland if it wins the election, as well as regulating the private rented market and capping energy prices.

He said: "Let's have a road to a fairer Scotland rather than a road to a second referendum with the SNP."

Ed Miliband said Labour would hold the SNP to former leader Alex Salmond's characterisation of the 2014 independence referendum as a "once in a lifetime" event.

Asked whether he would rule out a second referendum if he became prime minister, the Labour leader told 5 News political editor Andy Bell: "I don't want another referendum, definitely not.

"I'm giving you a very clear indication, Andy. There was a once in a lifetime decision - so called by the SNP - we'll hold them to it."

Asked how he felt about polls showing Labour apparently heading for defeat at the hands of the SNP north of the border, Mr Miliband said: "I bear a responsibility for everything that happens to the Labour Party, of course I do."