A Fairfax Nielson poll has National still in the lead, and while John Key remains the most popular choice for preferred Prime Minister, Helen Clark's rating has risen five points.
The poll, published on 18 October, puts National on 51% support, down one point from the same poll last month, and Labour also down one point to 33%.
The results are in line with the most recent TVNZ poll, but differ from the most recent Roy Morgan and TV3 polls which showed a narrowing of the gap between the two major parties.
The only minor party to register above the 5% threshold was the Green Party, which was up two points to 7%.
New Zealand First was on 3%, the Maori Party had 2% support and ACT and United Future were on 1%.
National leader John Key remains the most popular choice for preferred Prime Minister, rising two points to 43%, while Labour leader Helen Clark's rating rose five points to 35%.
The poll questioned 1160 people in the week until Tuesday 14 October, and had a margin of error of plus or minus 3.2 percentage points.
John Key says if there is weakness in Labour's numbers, it may translate into support for the Greens.
"I guess on Monday we'll find out exactly who the Greens will identify with, but I think we will anticipate that to be Labour, so that's in a sense a bit of a block, and there might be a bit of movement within the two."
Labour leader Helen Clark says the figures in the poll do not match up with recent polling she has seen, and she believes the gap is closing.
"I'm very very confident that the average in polling is showing the centre left and the right about even in polling terms."