The Tories have received a boost from a poll which put the party six points ahead of Labour.

Within hours a separate poll, by former Tory peer Lord Ashcroft, yesterday (mon) suggested that the party was neck-and-neck with the opposition.

Then a survey by ICM put the Conservatives on 39 per cent ahead of Labour on 33 per cent.

The dramatic lead is some distance ahead of other other polls in recent days.

ICM found Conservatives were up by 3 per cent and Labour down by 2 per cent, the Liberal Democrats unchanged on 8 per cent , Ukip down two points on 7 per cent and the Greens up three points on 7 per cent.

The figures are the best result for the Tories in an ICM poll since March 2012, before the so-called 'omnishambles' budget.

However, Martin Boon, of ICM Unlimited, said: "There is inevitably random variation between different polls, which generally falls within a 'margin of error' of plus or minus three points.

"The movement we've recorded since the March survey is within that normal bound, albeit only just."

Later a second poll, by ex-Conservative treasurer Lord Ashcroft, put the two main tied on 33 per cent, with Labour down by one point and Tories by three since a similar survey a fortnight ago.

UKIP and the Lib Dems were each up three points at 13 per cent and 9 per cent respectively, with the Greens down one at 6 per cent and the SNP unchanged at 4 per cent.

Lord Ashcroft, who quit the Lords last month, said: "Overall, just under half (48 per cent) thought that Britain was "going in the right direction", an increase of eight points since I last asked the question in January, while the proportion saying the country was heading in the wrong direction had fallen by seven points to 45 per cent.

"Swing voters, who say they don't know how they will vote or may yet change their minds, said 'right direction' by 49 per cent to 45 per cent."