National has dropped to 37 percent but still leads Labour on 33 percent in the latest 1 News / Kantar political poll.
The poll put the Green Party - which has faced leadership turbulence - on 9 percent of the vote, ACT on 11 percent, NZ First on 3 percent and Te Pāti Māori on 2 percent.
The numbers - if they held - would mean National and ACT together would have enough seats to form the next government.
It compares to the previous results at the end of May: National holding steady on 39 percent, Labour down on 35, Greens up on 10, ACT down on 7, and Te Pāti Māori holding the balance of power on 2 percent.
Then, Ardern had been on 33 percent and Luxon on 25 percent on 'most preferred prime minister' stakes.
National is fresh from its first party conference with Luxon as leader, where he announced a new welfare policy that has been roundly criticised by Ardern, by Labour and the Greens, and some support service groups.
None of that would have been public when polling was taken, but the ongoing struggles with rising inflation, a worker shortage, a health sector in crisis and heightened international tensions will all have factored into respondents' concerns.
Between 30 July and 3 August 2022, 1023 eligible voters were polled by mobile phone (504) and online, using online panels (519).
The maximum sampling error was approximately plus or minus 3.1 percentage points at the 95 percent confidence level.