Just 40 days before polls open, Ms Ardern has taken her party to the highest single-party result in the history of the Newshub-Reid Research poll - a whopping 60.9 per cent.

"It is high," a quietly chuffed Ms Ardern told Radio NZ on Monday.

"When it comes to the trends, we've seen a strong indication of support for what I would say is most likely to be the government's response to COVID and the recovery plan."

Ms Ardern has been cheered as she travels around New Zealand following its successful elimination of the virus from the community; it has been 87 days since a case was identified outside of the border regime.

The result is all the more extraordinary given Labour trailed opponents National by five percentage points, 41 to 46 per cent, in the last public poll before the arrival of COVID-19 to New Zealand.

National recorded just 25 per cent in the first poll since Judith Collins became the third opposition leader in as many months.

Replicated in parliament, National's caucus would be severed from 55 seats currently to roughly 32 representatives.

Labour would jump from 46 seats to around 77, enough to govern outright for the first time since the introduction of the mixed member proportional electoral system in 1996.

Former PM Helen Clark won three elections with 39, 41 and 41 per cent of the vote, relying on support from minority parties in each of her terms.

In 2017, Ms Ardern won just 38 per cent of the vote compared to National's 47 per cent, and relied on the support of two minor parties, NZ First and the Greens, to form a coalition.

If Ms Ardern's poll numbers hold, she would be the first leader to be able to govern with a clear majority since Jim Bolger's booming win in 1990.

She said Labour's internal polling showed a "a reasonably significant gap between (Labour) and the opposition" but they weren't home and hosed.

"I'm never complacent. I'm equally skeptical about the (polls) that are high as the ones that are low," Ms Ardern said.

"We have seen high support for the government ... but these are pretty extraordinary times.

"We'll be working very, very hard to earn the trust of New Zealanders."

For Ms Collins, the result ends the 61-year-old's honeymoon since becoming leader a fortnight ago after the surprise resignation of former leader Todd Muller.

Mr Muller left the top job after 53 days citing mental health challenges and is yet to return to parliament.

Ms Collins is seen as a sharper media performer and was expected to make the election more competitive.

Instead National's vote has plunged lower than the 31 per cent result that led to Simon Bridges' axing back in May.

"It must be a rogue poll," she told Newshub.

Campaign chief and deputy leader Gerry Brownlee agreed.

"These numbers aren't even in the same ballpark as our internal polls, other public polls and the hugely positive public response to our Leader Judith Collins," he said.

"Even with the most rigorous methodology, one in 20 polls will always be a rogue and this is clearly one of them."

Australian Associated Press