Labour leader Chris Hipkins has finally and officially ruled out working with New Zealand First in any government he leads.

The announcement had long been expected, with the relationship between the former coalition partners seemingly beyond repair.

Hipkins had previously said it was "highly unlikely" his party would work with New Zealand First again, and had already ruled out working with Peters as a Foreign Affairs Minister.

But on Monday afternoon, he confirmed there had been further internal conversations with his caucus, and he was finally ruling the party out altogether.

"Winston Peters has ruled us out. I'm happy to rule him out. It's clearly not going to happen."

Asked why he could not have said so sooner, Hipkins said New Zealand First's "pattern of behaviour" had escalated. 

"I'm not going to put up with overt racism in any government that I lead, as that's the sort of behaviour that Winston Peters and New Zealand First are indulging in. They won't have any role in a government that I lead."

Hipkins said there was "not a single person" in Labour who thought the party should be open to working with New Zealand First.

"I think everybody has been, I guess, wanting to just see how things shake down. But clearly, Winston Peters' recent behaviour has now made that completely unacceptable."

The behaviour included Peters’ recent comment made in the House to Green Party MP Lawrence Xu-Nan, saying "go back to your own country”.

Xu-Nan was born in China, but migrated to New Zealand as a child and is a citizen.

In a post on X, Peters said Hipkins had "severe learning difficulties."

"Why the media aren't lambasting him for "ruling NZ First out" after we ruled him out four years ago, then again twelve months ago, and repeatedly done so every month when answering the same stupid questions, is beyond a joke."

The definitive rule-out comes off the back of a poll showing a 3.7 point slump for Labour, and a more difficult path back to power.

The Taxpayers Union-Curia poll, released last Friday, had Labour on 27.8%.

The poll had current coalition parties National, NZ First and ACT, able to form a government, on 61 seats if the poll was replicated on election day.

The opposition - including the Opportunity Party, which National has already ruled out working with - would have just 59 seats - not enough to govern.

Hipkins, who had previously described the poll as "rogue", was sticking to his guns, saying Labour's polling had otherwise been steadily increasing since the last election in 2023.

"It's a real outlier. A rogue poll basically means an outlier, and it is an outlier when compared to the other publicly available polls."

The general election will be held on November 7.