Labour leader David Shearer's tough line on rival David Cunliffe, combined with a bold new housing policy, has boosted the party's support giving Labour and the Greens the numbers to govern alone, according to a new poll.



Tonight's One News-Colmar Brunton poll, taken a week after Cunliffe's demotion to the back benches for disloyalty, had Labour's party vote up three percentage points at 35 per cent, with the Greens up one on 13 per cent.



National was down one on 44 per cent, and NZ First slipped below the 5 per cent threshold to 4 per cent.



Labour received an even bigger boost in the electorate vote, up six points since the previous poll in late October, taking it to 44 per cent - one point ahead of National on 43 per cent.



Shearer's preferred prime minister rating also rose, up 4 points to 15 per cent, while John Key slid three to 39 per cent - the first time for four years the prime minister's rating has slipped below 40 per cent. NZ First leader Winston Peters was steady on 6 per cent.



The poll was taken between November 24 and 28, just over a week after Labour's annual conference exposed divisions in the party but also after Shearer's widely-praised keynote speech in which he outlined plans for a more hands-on policy including building 100,000 affordable houses over ten years.