Barry Coates 'being truthful' about Greens' attitude towards NZ First - Judith Collins

Judith Collins says Green MP Barry Coates was just telling the truth when he said the Greens would rather force a second election than support a Labour-NZ First coalition.

The comments earned Mr Coates a shellacking from his boss James Shaw, who told The AM Show on Thursday he was "imagining some scenarios" of how to punish the former Oxfam CEO.

NZ First leader Winston Peters said it was the "height of stupidity".

But Mr Coates has an unlikely ally in National Cabinet minister Judith Collins.

"I feel a bit sorry for Barry, because all he's doing is reflecting what Metiria Turei said the other day, and he's just doubled down a bit," she told The AM Show on Friday.

"But actually what it is showing is he's a new MP, and he's actually saying what he believes."

Ms Turei recently called NZ First's attitude towards immigration "very racist".

"Metiria was recently on television saying some pretty strong things against Mr Peters and his party, and I've got to say Barry is simply picking up on that," said Ms Collins. "He's being truthful."

Labour deputy leader Jacinda Ardern played down the drama, saying Mr Coates "went off the reservation" and was promptly chastised by the Green Party leadership.

"It's been pretty clear by the statements that his leader has made that he has most certainly spoken out of turn - it doesn't reflect the position of the Greens," she said.

"You can't tell me Judith you haven't had an MP go off the reservation before as well. It would be wrong for that to reflect on the wider caucus."

Mr Coates said the Greens had been discussing whether to back a Labour-NZ First coalition behind closed doors. Ms Ardern suggested this kind of chatter would happen on both sides of the political divide.

"I'm sure the Māori Party have very strong things to say about the ACT Party."