Labour has narrowed the Conservative Party's poll lead to just one point as the "Brown bounce" continues, according to a ComRes survey for The Independent.
It suggests that the measures in last week's pre-Budget report (PBR), including a new 45p-in-the-pound top rate of tax on incomes over £150,000, have proved popular among Labour's core voters.
The survey, taken between Friday and Sunday, puts the Tories on 37 per cent (down two points on last month), Labour on 36 per cent (up five points), the Liberal Democrats on 17 per cent (up one point) and other parties on 10 per cent (down four points).
The figures would give Gordon Brown an overall majority of 10 if repeated at a general election. The gap between the two main parties is the narrowest in any poll since January, when an Ipsos MORI survey put Labour one point ahead.
Labour's support among the bottom social group DE has risen from 35 per cent to 51 per cent over the past month. In contrast, Tory support among the same group has dropped from 39 per cent to one in four. At the same time, Labour's backing among C2 skilled manual workers has grown from 23 per cent to 35 per cent.
There are other signs that natural Labour supporters are returning to the fold. The number of Labour "identifiers" who say they will vote for the party has risen from 81 per cent to 87 per cent since last month. The number of natural Tories who intend to support their party has fallen from 95 per cent to 91 per cent. The proportion of Liberal Democrat "identifiers" who will back Nick Clegg's party is up from 76 per cent to 82 per cent.
Labour's support among women has risen by eight points and among men by two points, while Tory support among women is down five points. Labour's support is higher than a month ago in every age group except 35- to 44-year-olds.
The findings give Labour its best overall showing in a ComRes poll for this newspaper since September 2007, when it was three points ahead before Mr Brown's "honeymoon period" came to an end when he dithered over whether to call a general election.
They will come as a relief to Labour after the two polls published at the weekend suggested the "Brown bounce" was fading. But they make uncomfortable reading for the Tories.
Labour's private polling has found strong support among the party's traditional supporters for the Chancellor Alistair Darling's surprise decision to bring in a higher top rate of tax in 2011.
One Labour source said last night: "People wanted to see decisive action taken on the economy. What is hurting the Tories is that they have boxed themselves into a corner where they are the 'do-nothing' party."
Although some Tory MPs are worried that the party is suffering from a lack of economic policies, allies of David Cameron are urging them to "hold their nerve". They believe the polls will turn against Labour next year as the recession bites.
Tory officials said it was "completely untrue" that the party had said nothing about the downturn. They pointed to other surveys since the PBR which found that people did not believe the Chancellor's package would have much impact.
ComRes telephoned 1,005 GB adults on 28-30 November. Data were weighted by past vote recall. ComRes is a member of the British Polling Council and abides by its rules. Full tables at www.comres.co.uk