In a highly unusual move, the Labour Party has released some details of its internal polling.
Labour leader Andrew Little objected to the results in the latest One News Colmar Brunton poll that had National steady on 48 percent, Labour down two points to 26 percent, the Green Party up one point to 13 percent and New Zealand First up two points to 11 percent.
Mr Little told reporters at Parliament that the poll stood in "stark contrast" to other polls including Labour's internal polling and other published polls.
"So far at odds with those polls that I reject the result ... so I just think the results aren't accurate.
"Here's what the TVNZ poll requires you to believe - that two years on from the election, with their failure to deal with housing, their failure to deal with homelessness, their failure to deal with rising crime, their failure to deal with education ... that somehow the government is as popular as ever.
"That simply isn't credible," Mr Little said.
When asked for Labour's internal polling, the party released the headline figures, which had National on 40 percent and Labour on 31 percent.
Labour's media staff said the 40 percent result for National should be treated with caution, as it seemed to be unusually low, and the trend was for National to be around the 43 to 44 percent mark.
The polling also showed a 46 percent "unfavourable" result for Prime Minister John Key as National Party leader, compared with 33 percent for Mr Little. The "favourable" result was 52 percent for Mr Key, and 49 percent for his Labour counterpart.
The Labour poll, carried out by UMR, covered the period between 31 August to 5 September and surveyed 750 people, with a margin of error of 3.6 percent.
The poll is done every fortnight.
The latest result from RNZ's Poll of Polls, compiled by Colin James, showed National at 45.7 percent, Labour on 28.5 percent, the Greens on 13.5 percent and New Zealand First on 9.5 percent.
'They can believe whatever they want to believe'
Mr Key said Labour releasing its own internal polling seemed a bit desperate.
"At the end of the day, they can believe whatever they want to believe, there's a slew of public polls out there - none of them really look like Labour is polling, but to be frank I'm not really focused on their polling.
"I focus on doing my job and in the end we'll have a poll and it's called the general election."
He said it did not put any pressure on the National Party to release its own Curia polling.
"Part of me would love to, but no I don't think it should."