A new political poll puts National's support at 39 percent, while Labour is down two points on 35 percent. If Election 2023 delivered these results it would result in a hung Parliament.
The latest 1 News / Kantar Public poll put the Green Party up 1 percent on 10, with ACT down on 7 percent and Te Pāti Māori on 2 percent.
That would mean National would get 51 seats in Parliament, ACT nine, Labour 45, 13 for the Greens and two for Te Pāti Māori.
On these numbers, neither National nor Labour would be able to form a government with their traditional partners.
It would fall on Te Paati Māori to either play kingmaker for National or choose Labour in what would be a hung Parliament.
In the preferred prime minister stakes, the poll put Jacinda Ardern on 33 percent, down one, while Christopher Luxon was steady on 25 percent. David Seymour dropped two points to 3 percent while Chloe Swarbrick had 2 percent of the support and Winston Peters 1 percent.
The poll is the first since the Budget earlier this month but also coincides with a cost of living crisis.
Last week, the Reserve Bank lifted its official cash rate by 50 basis points (half a percentage point) to two percent, and signalled on current conditions it could hit close to four percent by the end of the year.
National leader Christopher Luxon has criticised the amount of spending in the Budget and has accused the government of wasteful spending.
In the last 1 News / Kantar Public poll in March, National overtook Labour, with 39 percent support compared to Labour's 37 percent.
Ardern was on 46 percent and Luxon on 45 percent for the most preferred prime minister.
The latest poll was conducted between 21 and 25 May with a sample size of 1002 eligible voters, with half polled online and half via mobile phone, a margin of error of plus or minus 3.1 percent and 95 percent confidence, according to 1 News.
National Party leader Christopher Luxon said it was too soon to discuss how it might form a Government come Election 2023.
"Look it's really very premature and it's a long way away and as you said it is hypothetical.
"My job is to make the case for National as compelling as possible for voters to be considering come 2023."
ACT leader David Seymour said the results showed New Zealanders wanted change.
"The momentum over the last 18 months shows we're edging closer to a change of Government and a new Government in which ACT plays a significant role delivering real change.
"So we're very encouraged."