The National Party has slumped to just 21.3 percent while ACT is sitting on 14.9 percent of the vote, a new poll shows.
Right-wing lobby group the New Zealand Taxpayers' Union (NZTU) commissioned the poll, carried out by market researcher Curia.
One thousand eligible New Zealand voters took part in the poll, which was conducted between September 5 and September 9.
The poll has Labour at 45.8 percent, the Green Party on 9.6, New Zealand First at 2.7, and the Māori Party on 1.2. 'Other' parties make up 4.5 percent.
National's result of 21.3 percent is just above its worst-ever election outcome when it received 20.93 percent in 2002.
The latest Newshub-Reid Research poll released in August painted a similar story for the ACT Party, which went up 4.2 points to 11.1 percent.
National couldn't quite crack the 30 percent threshold in that poll either - it finished on 28.7 percent.
The NZTU poll was one of two released on Wednesday, the other being the UMR poll.
UMR has Labour on 45 percent, National at 26, ACT on 13, the Green Party at 6, and New Zealand First on 4.1.
That poll was conducted between August 31 to September 6 and surveyed 1050 people.