National and the Greens have been major movers in the latest One News Colmar Brunton poll with National up six points to 51 per cent and the Greens down by five to 8 per cent.
Labour remains on 34 per cent despite being under the new leadership of David Cunliffe since September.
National could govern alone on 51 per cent.
The Maori Party and the Conservatives have had no change and are on 1 per cent; New Zealand First is on 3 per cent, down one point on the last Colmar Brunton poll in October.
United Future and Act registered no support.
Prime Minister John Key is preferred Prime Minister by 43 per cent, the same as the October poll.
Mr Cunliffe is down by two points to 10 per cent, and New Zealand First leader Winston Peters is steady on 4 per cent.
National began the year with a policy package to reform school leadership structures.
Labour's big push has been on baby bonus scheme and the Greens have launched a solar energy policy.
The Greens have been subjected to sustained attacks by National, especially over events surrounding the Greens and internet mogul Kim Dotcom.
Greens co-leader Russel Norman said his party would try to block the extradition of internet mogul Kim Dotcom to the United States if it was part of the next Government.
Dr Norman visited his Coatesville mansion last year in a bid to dissuade him from setting up the Internet Party in the belief it would damage the Greens.
Mr Dotcom has said he would throw his weight behind another party if the Internet Party did not look like crossing the five per cent threshold.
Greens co-leader Metiria Turei accused National of racism when its ministers drew contrasts between her designer clothes and her advocacy of the poor.
- Audrey Young of the NZ Herald