The Maori Party has surged in support in the latest poll - which is the second in which Labour's Jacinda Ardern rated higher as preferred Prime Minister than Andrew Little.
A One News Colmar Brunton poll released tonight also shows a drop in support for Bill English as preferred Prime Minister, and a pick-up in support for the Maori Party, up from 1 to 4 per cent.
National remains steady on 46 per cent, as do Labour (30 per cent) and the Green Party (11 per cent).
New Zealand First drops 3 per cent to 8 per cent support.
On the question of preferred Prime Minister, Bill English is on 26 per cent - a drop of 5 per cent since the previous polling in February, and well below John Key's rating of 36 per cent in November.
Next most popular are Winston Peters and Jacinda Ardern on 9 per cent, with Ardern climbing 5 percentage points since being made Labour's deputy leader in March.
Little is steady on 7 per cent.
The poll is the second since Ardern was made deputy leader and the second to have her ahead of Little as preferred Prime Minister - a Newshub Reid-Research poll on Tuesday had Little on 8.3 per cent while Ardern was up by almost 8 points to 10.5 per cent.
Maori Party co-leader Te Ururoa Flavell told 1 News that New Zealanders were "coming to grips with our approach".
"And very much seeing the pragmatic approach that we take."
The One News Colmar Brunton poll of 1000 voters was taken March 18 to 22, and after the Maori Party announced on February 20 an agreement with the Mana Party to worth together until September's general election.
Under the agreement the Maori Party won't stand a candidate in the Tai Tokerau electorate and Mana won't stand in the other six Maori electorates.
In a media interview after the deal was announced, Little said the Maori Party was not kaupapa Maori because of its agreement with National and concession on important issues affecting Maori.
Labour MPs who hold Maori seats announced on Tuesday they would not run on the party list, which Little described as a direct challenge to the Maori Party.
The decision is partly designed to stop voters from casting "two-for-one" votes, in which they gave their party vote to Labour - knowing that the party's Maori MPs will get elected on the list - while voting for the Maori Party or Mana candidate.
Little told the Herald the polling did not reflect the feedback to Labour about how Maori voters viewed the Maori Party.
"Which is not very favourably. They are seen as having been shackled to the National Government for nine years and stood aside and let Maori homeownership fall, Maori homelessness grow and a whole heap of other things get worse.
"I just don't detect, and neither do the Labour Maori MPs, detect any appetite among Maori voters for the Maori Party having a role in Government."
On Labour's showing in the poll, Little said the results were unusual.
"It's not consistent with the amazing turnout we are getting at our meetings and the feedback all MPs are getting. The poll's not bad for us, but there's been no change in the last six weeks, which doesn't seem right to me."
Under the poll results National (56 seats) would be able to form a Government with the Maori Party (5 seats), Act (1 seat) and United Future (1).
That assumes all those support partners each wins an electorate.
The poll of 1000 voters has a margin of error of +/-3.1 per cent.