For some reaason Roy Morgan have just released their poll done through September so in the context of an election campaign it is a bit out of date but may be of interest on the eve of election day (note that about 1.7 million people have already voted).
- Labour 47.5% (August 48%)
- National 28.5% (August 28.5%)
- Greens 9.5% (August 11.5%)
- ACT 7% (August 6%)
- NZ First 2.5% (August 2.5%)
- TOP 1.5% (August 1%)
- Maori Party 0.5% (August 0.5%)
- Other 3% (August 2%)
Those results aren’t a lot different to other recent polls, although they have National a bit lower and Greens a bit higher.
Trends seem quite steady (also like other polls):

Government confidence is also quite stable.

This latest New Zealand Roy Morgan Poll on voting intention was conducted by telephone – both landline and mobile – with a NZ-wide cross-section of 911 electors during September. Of all electors surveyed 6% (up 0.5%) didn’t name a party. Electors were asked: “If a New Zealand Election were held today which party would receive your party vote?”
http://www.roymorgan.com/findings/8543-nz-national-voting-intention-september-2020-202010142349