Labour look set to be reduced to a rump in the next Scottish Parliament after a new poll suggested the party might win only 25 seats. The TNS poll released today suggests the SNP are set to increase their majority at May’s election, with analysis from the Scotland Votes site suggesting the party could gain 78 seats. The Tories would be on 15 with the Greens on nine and the Liberal Democrats on two.

In the poll of 1035 over-16s, the SNP at were at 58 per cent in the constituency vote, unchanged from last month. Labour were down by three points to 21 per cent. Both the Tories and Lib Dems remained unchanged at 12 per cent and four per cent respectively.

On the the constituency vote Labour had dropped five points to 20 per cent while the SNP gained two to take them to 54 per cent.The Tories were up one per cent to 12 and the Greens were up four to nine. The Libs Dems lost a point to take them to four per cent.

Tom Costley, the head of TNS Scotland, said: “The past month has seen the political agenda return to devolved issues such as healthcare and transport, with opposition politicians attacking the SNP government’s record on hospital provision and on maintenance of the Forth Bridge. The criticism appears to have had little or no effect on support for the SNP.

“One interesting feature of the poll is that the number of those who say they are certain to vote in 2016 has been declining, and now stands at 58%, down from 64% as recently as the TNS poll in September. The turnout in Scotland in the May 7 general election was 71%.

“It may be that, faced with the SNP’s huge lead in the polls, a number of voters feel that their vote would not influence the result. However, it seems unlikely that turnout in May will be as low as the 50% recorded in the 2011 Holyrood elections.”

Pollsters also asked those taking part about the issues that would affect their vote. Health was at the top of the list with 51 per cent and the economy and education in joint second.

The voters were also asked for views on replacing Trident, with 38 per cent opposing renewal, 29 per cent supporting, and a massive 26 per cent undecided.Support for the new weapons was 47 per cent in the over 55s, three times as strong as support among those aged 16 and 34.