SIX in ten voters plan on backing the SNP in May's Holyrood election, as Nicola Sturgeon's party extended its huge lead in the polls.

A new survey for TNS put the nationalists on 60 per cent in the constituency section, an increase of three points, with Labour trailing on 21 per cent.

However, despite its numbers remaining unchanged, Kezia Dugdale's party increased its lead over the Tories, who dropped four points to 13 per cent. Just four per cent of voters plan on backing the Liberal Democrats with their first vote, an increase of one per cent.

On the regional vote, the SNP is on 55 per cent, Labour 21 per cent, the Tories 13 per cent, the Greens six per cent and the Lib Dems on four.

The Herald:

The poll indicates that Labour's flagship policy of adding 1p to income tax rates to offset public spending cuts has not led to a breakthrough, with the research beginning on February 3 - days after it was announced - and ending on February 24.

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Tom Costley, Head of TNS Scotland, said: "There is no evidence from this February data that the Conservatives in Scotland have made any progress in narrowing the gap with Labour, to claim to be the second party – indeed, if anything, they have fallen back a little. With nine weeks to go, time is running out for opposition parties to make real inroads into SNP polling dominance."

The SNP has a similar large lead in both ballots among men and women, across all social classes and in all age groups, with the exception of among those aged 65 and over where their lead over Labour is only 2 per cent.

According to PR agency Weber Shandwick's online seat calculator, the result would see the SNP win all but two constituencies and nine list seats, giving the party 80 MSPs overall and an increased majority on 2011. Labour would return 27 MSPs, the Tories 15, the Greens five and the LibDems just two. 

Just over 1,000 adults, in face-to-face interviews, were also asked about the nationalists' record in Government on domestic issues.

Despite opposition parties relentlessly attacking the SNP's record on education, 34 per cent said they believed the party's record is good compared to 23 per cent who chose "poor". 35 per cent said neither and nine per cent didn't know.

On the NHS, 35 per cent thought the SNP's performance is good, compared to 30 per cent who believe it is poor and 31 per cent picked neither.

Meanwhile, on the economy and justice, respondents were less impressed. Just 22 per cent backed John Swinney's handling of the economy as good, with two per cent more picking poor. On crime and justice, 23 per cent said the SNP's performance had been good with 28 per cent saying poor.

The Herald:

Mr Costley added: "Six months after we last asked these questions - during which time the opposition have been challenging the SNP Government on their record - there has been next to no change in public opinion of their management of the economy, health service and crime and justice. With focus on the next few months likely to be on Europe, opposition parties in Scotland are likely to find it ever harder to make their arguments about the government’s performance heard."