NICOLA Sturgeon has attempted to steer the election debate away from the constitution in the final 48 hours before Scots go to the polls, amid last minute fears her party might not achieve an overall majority at Holyrood.

During a visit to Aberdeen, she said job creation would be "at the heart of a re-elected SNP Government’s agenda".

Senior colleagues also issued statements saying "education will be the defining priority" and pledging to invest in "our most cherished public service," the NHS.

The claims, on the penultimate day of campaigning before Thursday's poll, were seen as a bid to shift the debate away from the SNP's plans for a second independence referendum.

The issue has dominated the final days of the election battle, with Labour, the Conservatives and Liberal Democrats all denouncing the Nationalists' pledge to push for a re-run of the 2014 poll if they can increase support for leaving the UK.

The final televised election debate, broadcast by the BBC on Sunday night, showed how divisive the question has become, as sections of the audience lent vociferous support to either side.

Ms Sturgeon has said Holyrood should have the right to stage a second referendum at a time of her choosing but, as the row rumbled on, David Cameron's spokeswoman yesterday repeated the Prime Minister's view the question had "been settled for a generation".

The bid to shift the debate back towards bread and butter election issues came as senior SNP sources betrayed last minute jitters about the party's chances of gaining a majority at Holyrood.

A new poll, by Survation, put support for the SNP on 49 per cent in the constituency vote and 43 per cent in the regional, or 'list' ballot.

According to the widely-used ScotlandVotes seat predictor, that would give the Nationalists 69 of the parliament's 129 seats.

But a source said: "It is possible we could out-poll our performance in 2011 and still fall short of a majority because of how things work out on the list.

"Getting the vote out is crucial.

"We are hoping for a record turn-out for a Holyrood election."

To date, the highest turn-out was 59 per cent in the first Holyrood election in 1999.

At the last poll five years ago, turn-out was 50 per cent. Then, the SNP achieved a majority of seats with 45 per cent of the popular vote.

Ms Sturgeon stepped up her party's "Both Votes SNP" campaign during her visit to the North East, when she also launched a new SNP business magazine.

Visiting Bert Clark, a party member celebrating his 100th birthday, she said: "It was fantastic and inspirational to meet Bert and it was a reminder of the historic opportunity for the SNP to secure an unprecedented third term in government."

Scottish Labour remained confident of winning more seats than the Conservatives, despite the latest poll putting the two parties neck and neck.

Survation found 21 per cent of Scots were planning to back Labour in the their constituency, ahead of the Tories on 19 per cent.

However, the Tories retained a slight lead - by 20 per cent to 19 per cent - in the race for regional votes.

If repeated on polling day, it would give the Tories 24 seats, one more than Labour, according to the ScotlandVotes tool.

Labour sources insisted their own polling showed a brighter picture.

Insiders believe there are four constituencies where they still have a chance of upsetting the odds and holding off the challenge of the SNP.

In addition to Edinburgh South, seen as Labour's best hope, they include Renfrewshire South, East Lothian and Coatbridge & Chryston.

Elsewhere, fierce battles are being fought between the SNP and the Lib Dems in Orkney and Shetland, and between the Nationalists and Conservatives in seats in the South of Scotland.

Polling expert Chris Hanretty, of the University of East Anglia, said there was a 99 per cent chance of the SNP winning a majority.

He also calculated the Tories had a one in four chance of equalling, or bettering, Labour's haul of seats.

His prediction model, using long-term constituency polling data from TNS-BMRB, found the SNP was most likely to win 70 out of 129 seats, with Labour taking 26, the Tories 22, the Liberal Democrats five and the Greens six.

Dr Hanretty said: "There's a one in four chance the Conservatives could either beat Labour or finish equal on seats, and they're exceedingly likely to register their best-ever seat tally.

"It's gone from a what-if scenario to a real risk for Labour.

"What's notable is not just the fact that the SNP looks set for another majority, but also the size of their lead over the second-placed party, whichever party that might turn out to be."