Prime Minister Jacinda Ardern says she won't censor New Zealand First ministers' language

Prime Minister Jacinda Ardern won't censor Winston Peters' language after he labelled a reporter a "psycho", but says she wouldn't have said that.

The Deputy Prime Minister lashed out at a Newshub journalist on Monday while being questioned over a New Zealand First-linked company that applied for Government funding. 

It was revealed last week that NZ Future Forest Products - which has Peters' lawyer Brian Henry as a founding director - applied for money from the Provincial Growth Fund (PGF) and the One Billion Trees programme. 

Both programmes are led by New Zealand First Minister Shane Jones, who said he sought conflict of interest advice and removed himself from ministerial discussions.

Official documents revealed by RNZ show government officials engaged with NZ Future Forest Products "at various times" between March and October 2019 in relation to the PGF application, which was declined this month.

The Deputy Prime Minister said having Jones excuse himself from the decision-making showed the system worked.

When asked whether he would be comfortable with the Auditor-General looking into the company's dealings - as National has suggested - Peters labelled the reporter a "psycho", saying there were no grounds for that.

"Yes, I am calling you a psycho, because you can't even make out the case," Peters said. 

"You've got to be psychologically maladjusted if you can't make a case for an investigation you think is sound."

On The AM Show on Tuesday, Prime Minister Ardern said Peters' comments didn't break the Cabinet Manual and she wouldn't censor her ministers.

"I cannot control, and nor am I the chief censor of Parliament and nor will I ever be and nor has any Prime Minister ever been the chief censor of Parliament," Ardern said.

"You know I have a particular style, but am I going to enforce that across the New Zealand Parliament and force everyone to adopt my style of politics? No, I'm not."

But it's not language she would have used. 

"I have openly said, you will know it's not language I would use," she told The AM Show.

"I wouldn't say it, it's not the way that I conduct myself in Parliament."

RNZ also revealed last week that Peters' partner, Jan Trotman, was appointed as NZ Future Products company director five days after the first application was rejected in August. Peters defended Trotman on Monday, saying she wasn't a director when applications were made. 

"The person you're attacking, in this case, my partner, was not even part of the business when the application was made or when it was finalised," Peters told reporters.

"If it came to the question of whether there was a conflict of interest, well in the case of one person who wasn't even then a director and became an executive director after the failure, how would that person be in any way caught by conflict of interest?"

Ardern said Peters "retaliated" as his family was being "brought into questions". She said she has "sympathy for how difficult that can be".

On whether New Zealand First Ministers - including Jones, who made controversial remarks about farmers at a protest last week - were acting out to get attention, Ardern didn't agree.

"I deal with them day in, day out and there is nothing that I have seen at all that suggests that there is anything in particular here," she told The AM Show.

"On the issue of the rednecks, I did have a conversation. It was Shane who came to me in that first instance and said he accepted that language wasn't great. Having said that, I also saw some of those signs and posters out there in that protest, they were pretty borderline."