A second poll released this week has Act closing in on National.
On Wednesday the Taxpayers' Union released a poll by Curia, the polling company associated with National, which showed National on 22.5 per cent, up 1.2 per cent, while Act rose 1.7 points to 16.6 per cent.
Labour dropped 1 percentage point to 44.8 per cent. The Greens dropped 3.2 points to 6.4 per cent.
Earlier, a poll by Talbot Mills Research also showed Act trailing National by around 6 per cent.
While no party saw a major move in the October poll "the cumulative effect is significant with the gap between the centre-left and centre-right closing" the Taxpayers' Union and Curia said in a statement.
"In September the gap between National/ACT vs Labour/Green was a 19.2 per cent. In this October poll the gap is down to 12.1 per cent."
Curia said the poll was conducted October 3-11, with 1000 eligible voters contacted by phone.
The polls could add pressure to National leader Judith Collins, with almost all of the recent polling showing National's support dropping.
As with the Talbot Mills poll, David Seymour was also the most popular choice on the right as preferred Prime Minister in the Taxpayers' Union poll.
While Jacinda Ardern was by far the most popular choice on 47.2 per cent, Seymour was the preferred Prime Minister of 12.3 per cent of those surveyed, while Collins was 5.2 per cent.
The poll revealed a strong split across gender lines, especially for the Act Party. According to the Taxpayers' Union poll, 24.1 per cent of men indicated they would vote Act, compared to just 8.9 per cent of women.
National was preferred by 25.6 per cent of men and 19.3 per cent of women.
Labour was preferred by 57.8 per cent of women and 32 per cent of men, while the Greens were supported by 7.3 per cent of women and 5.4 per cent of men.
The poll shows Act ahead of National among Auckland voters and rural voters, while trailing elsewhere.