Pressure is building on National leader Judith Collins as a Newshub-Reid Research shows Act continuing to siphon away the party's support.
Labour is down 0.3 points to 42.7 per cent but National also fell in the poll published tonight, dropping 1.8 points to 26.9 per cent.
Act is up 4.9 points to 16 per cent.
Jacinda Ardern is on 41.7 per cent as preferred prime minister. That's down 3.8 points from the last poll.
National leader Judith Collins is down 2.1 points, sitting at 6.1 per cent.
That's almost half Act leader David Seymour's preferred prime minister rating, which had climbed 3.3 points to 11.9 per cent.
The poll, conducted between November 10-17, showed Labour holding steady from a previous poll in August where they were at 43 per cent.
The Greens were at 7.2 per cent support, down 1.3 per cent, while Te Pāti Māori and New Zealand First both were around 2 per cent.
If an election were held today, Labour and the Greens would still be able to hold power but, based on polling, Act would double its number of MPs to 20.
Collins' leadership of National has been questioned since she led the party to a landslide defeat in 2020's election.
National's Christopher Luxon and former leader Simon Bridges, both who have been mooted as possible replacement for Collins, both ranked at 2.5 per cent support.
"We're not into crushing people," Seymour told Newshub when asked about his party's rise in support.
Another poll last week by 1News Colmar Brunton found Labour Party support at 41 per cent, National at 28 per cent, Act at 14 per cent and the Greens at 9 per cent.
The Newshub-Reid poll has a margin of error of 3.1 per cent.