Meanwhile, In an interview with Mike Hosking on Newstalk ZB this morning, Ardern remained stoic in her stance that Deputy Prime Minister Winston Peters had every right to go ahead with a private prosecution against his own Government.
The New Zealand First leader announced he would begin new legal action this week and is seeking $450,000 for alleged breach of privacy in relation to the leaking of details of his superannuation overpayment, including against the Ministry of Social Development.
In his sights are the chief executive of the Ministry of Social Development, Brendan Boyle; State Services Commissioner Peter Hughes; the Attorney-General on behalf of the Ministry of Social Development, Paula Bennett; and the former National State Services Minister and former Minister of Social Development, Anne Tolley.
Hosking told Ardern the timing seemed "extraordinary" that just days from taking up reins as acting Prime Minister he would extend his legal action.
"It hasn't affected his ability to do the job to date, it's one extra step in a case that's a private matter for him and a decision for him. But, as I say, this is not new and has been going on for some time."
However, when questioned whether the Prime Minister can have "private matters", especially as the legal action involved the people he was in charge of, Ardern said he could.
"Yeah, it's a decision that he's made, not as a minister, before he even became acting prime minister, that he was pursuing this issue of privacy. It's not something that I have been involved in, and nor should I be, because it is a decision ultimately for him."
Ardern said if got to the point involving court, Peters would excuse himself from any involvement in decisions being made around the case.
"So the very people in the Cabinet that he leads would be making the decision as to whether they fund the people he's suing?" Hosking asked.
"Independent of him, he would not be involved," she replied. "It's at the discretion of the Attorney General."
When asked whether she had talked to Peters about the prosecution, the PM replied "not in great detail".
"If someone wishes to pursue an issue of privacy, it's not for me to dictate whether or not they should or shouldn't have the right to do that. That would be inappropriate. It's a decision for him to make as an independent person and it wouldn't be right for me to persuade or dissuade someone from pursuing something. That is for them as an individual.
"This is a matter that happened long before the election."
The PM was also questioned about Andrew Little's premature hope of repealing the three strikes law, which had to eventually be ditched because of a lack of support from New Zealand First.
Speaking yesterday, he wouldn't confirm how thorough his consultation had been with his coalition colleagues.
Ardern told Hosking that "nothing is set in stone until it's gone through cabinet, we all knew that".
"It's a coalition government. Everything we do is negotiated, everything, and I think that speaks to our strength the fact that this is one small part of that reform package."
Hosking told Ardern that when people are in jail they're not committing crimes.
"That logic only holds true if you keep people in there forever and for some low level crime that's not realistic," she replied. "It's an expensive way to deal with the problem. What we need are more effective interventions.
"The people who should be in prison need to be in prison but there are a range of options to deal with lower-level offending that we need to explore so that ultimately we are all a lot safer."
As for the Government's announcement tomorrow about Waikeria prison's refurbishment going ahead, Ardern said Labour had never supported larger prisons.
"But Waikeria is not in great shape so we've had to deal with that particular issue as well."
