The latest Newshub-Reid Research shows Labour could govern alone three weeks out from the election.

Labour polled 50.1 per cent while National polled 29.6 per cent.

The latest poll may indicate that National has been hurt by its $4 billion fiscal error in its alternative budget.

ACT is up three points to 6.3 per cent, while the Greens are up to 6.5 per cent - meaning both parties could get eight seats in Parliament if these numbers translate on election day. 

Labour, meanwhile, would get 65 seats, while National would get 39, losing 17 MPs. 

New Zealand First is 1.9 per cent, not enough to enter Parliament. New Conservatives are currently polling higher, on 2.1 per cent. 

Judith Collins told Newshub she was "getting a very good vibe on the ground" and said she wouldn't resign if she lost the election.

"Certainly not," she said.

Collins said her party would understand they'd "been through some difficulties".

PM Jacinda Ardern told Newshub there hadn't been an MMP election which had a party able to govern alone but it was premature to assume that.

ACT leader David Seymour said the poll result energised their campaign.

NZ First leader Winston Peters told Newshub he still thought he was going to get back into Parliament.

"I don't have any regard for your polls," he said.

Ardern remains the preferred Prime Minister for 53.2 per cent of those surveyed (down 8.8 percentage points). Judith Collins' popularity has risen by 3.1 percentage points to 17.7% in the preferred PM stakes.

The margin of error is 3.1 per cent.

Last week's 1 News Colmar Brunton poll put Labour on 48 per cent, National on 31 per cent, Act on 7 per cent, the Greens on 6 per cent and NZ First languishing on 2 per cent.