Prime Minister Jacinda Ardern says she has no intention of going anywhere ahead of next year's election after a political poll had Labour at its lowest since 2017.

Ardern herself sat at 30 per cent for preferred prime minister - just 8 per cent above National Party leader Christopher Luxon - in Monday night's 1 News-Kantar poll.

"We've gone through tough times as a nation, and we've been through plenty of them before," Ardern said, adding of the 2023 election "a year is a long time".

"You think about where we were a year ago... we were announcing our reconnecting plan and within a week or so Delta arrived.

"It feels like we've had three years since that period. A year in this current environment is a long time and there's a lot for us to do and that's what I'm focused on."

National and Labour each slipped two points to 37 per cent and 33 per cent respectively.

Benefiting from the falls of the two major parties was Act, up four points to 11 per cent. That brought the right bloc to 48 per cent and 62 seats – enough to form a government.

Senior Labour ministers also strongly defended their leader and party record, declining to entertain questions about if and at what point they might stand.

"I think you probably just want to reflect on whether or not you've ever in the history of polls asked whether the preferred prime minister of the country should step down," Deputy Prime Minister Grant Robertson said.

"So no," he said of at what point in the polling he might put up his hand.

"We are obviously in a pretty tough time for a lot of New Zealanders, and this winter with a lot of people sick.

"We do have cost of living issues for a lot of people. But I'm very optimistic.

"So I simply it's hypothetical, and I don't think it'll happen."

Police and Education Minister Chris Hipkins used the same line of defence, repeating that Ardern remained the preferred prime minister.

"There isn't a vacancy, there is not going to be a vacancy for quite some time yet.

"Maybe in 10 years' time when there might eventually be a vacancy maybe that's something to talk about at that point. But at the moment it's not on the table."

Ardern said she believed there were a lot of areas where things could improve over the next year in the post-Covid recovery.

"It's undeniable, you look around the world, governments are navigating an incredibly difficult post-Covid recovery.

"The difference for New Zealand is that there is a lot of space for us to perform particularly well relative to others.

"When you think about our tourism coming back, and skilled migration coming back, we have opportunities that we need to grab."

Monday's poll was conducted between July 30 and August 3. The last such poll was run over May 21 to 25.

Recent co-leadership issues in the Greens do not appear to have hurt the party too much, with it dropping just one point to 9 per cent. Te Pāti Māori is steady on 2 per cent.

On those figures, Labour would receive 44 seats and the Green Party 11, adding up to 55 - well short of the 60 needed, even with the potential three seats from Te Pāti Māori.