JIM Murphy and Nicola Sturgeon will meet in their first televised election debates this week in a 48-hour burst of publicity that could decide whether Scottish Labour can avoid a wipe-out.

The party leader and the First Minister will clash in an STV leaders debate in Edinburgh on Tuesday, which includes LibDem Willie Rennie and Tory Ruth Davidson.

Murphy and Sturgeon then spar again the next evening in a six-way BBC debate from Aberdeen, which brings in Green co-convener Patrick Harvie and Ukip MEP David Coburn.

The long-awaited confrontation comes as opinion polls continue to show a gulf between the SNP and Labour, pointing to just a handful of Labour MPs left in Scotland on May 8.

Sturgeon has also been buoyed by a widely praised performance in last week's leaders' debate on ITV, and the collapse of yesterday's story claiming she wanted David Cameron as PM.

A new Opinium survey found the ITV debate gave Ed Miliband a six-point boost to his personal rating, but left the parties virtually unchanged, with both Labour and the Tories on 33%.

The Scottish TV debates offer Murphy a chance to deflate the SNP bubble, but could also prove lethal to Labour's chances if he puts in a poor performance.

In his only previous debate with Sturgeon, at Glasgow University last month, Murphy stumbled over a question on drugs, and was forced to clarify that he had not sniffed glue as a child.

A Labour insider also told the Sunday Herald that feedback from the party's internal polling found Murphy was seen by many voters as "insincere".

A senior SNP campaign source said: "These are big debates, just as important as the ITV Leaders' Debate.

"We take nothing for granted, but believe that the SNP's commitment to boosting progressive politics in Scotland and across the UK has struck a chord - it leaves Labour, the Tories and Lib Dems arguing for the old politics of a binary Westminster system which people have long-since left behind."

Ruth Davidson last night challenged Sturgeon to use the debate to rule out a second referendum, and stick to the SNP's previous description of it as a "once in a lifetime" event.

The Tory leader said: "When asked about this in recent weeks, Nicola Sturgeon has tried to bat the issue of another referendum away by saying it's for next year's Holyrood elections.

"This isn't good enough. It's an open secret in Holyrood that Nicola Sturgeon is considering calling another referendum as soon as she thinks she can win one.

"As she prepares to face more TV debates this week, she needs to come clean with the people of Scotland: is she planning another referendum and if so when?"

With just over 30 days until polling, the SNP yesterday ramped up its campaigning with 300 street stalls.

It also announced 2000 new recruits since the ITV debate, taking its membership to 105,000.

Ed Miliband yesterday told Labour activists in Doncaster he felt "a growing sense of confidence" that Labour would win the election.

He said: ""I feel the momentum is with us in this election. In 30 days time I believe we are going to elect a Labour government."

The Labour leader will today announce plans to build 125,000 new homes by using £5bn from Tory chancellor George Osborne's new ISA scheme for first time home buyers.

Labour said the money would come from channelling the investments that banks and building societies make off the back of the new ISA into housing, with savers guaranteed the same rate of return and withdrawal terms.

Labour also claimed Tory tax policy had left households £1,100 a year worse off on average.

The Scottish Secretary will today warn working Scots would pay £400 a year more under SNP income tax plans than under the LibDem one to raise the starting threshold to £12,500.

Alistair Carmichael said the SNP plan to raise the threshold by the rate of inflation, currently 0%, meant people would "get no extra help at all".

He said: "It is wrong for the SNP to claim they are in favour of working people, yet oppose a tax cut for them. We would put another £400 a year back into the pockets of working men and women in Scotland. The SNP talk a good game about helping the less advantaged, but they don't have a redistributive policy to their name."