'No concerns, absolutely none' - Jacinda Ardern has confidence Winston Peters will do a great job as Acting PM while she's on maternity leave

Prime Minister Jacinda Ardern has absolutely no concerns about Winston Peters' ability to perform the role of Acting Prime Minister while she is on maternity leave.

Mr Peters will fill on for the PM while when she takes time off to look after her soon to be born child. Source: Breakfast

Ms Ardern, who is due to give birth on June 17, and Mr Peters released a jointly crafted letter yesterday outlining the arrangements of her six weeks of maternity leave.

When quizzed about Mr Peters' reputation and his ability to lead in her absence, on TVNZ1's Breakfast today, the prime minister was unequivocal.

"I would challenge that (Mr Peters' reputation)…keeping in mind, Winston Peters has been Deputy Prime Minister before, he has been Acting Prime Minister before, this is not new," she said.

"I have absolutely no concerns, absolutely none, and nor should anyone else."

"We already have a relationship that means where we're in pretty close contact with each other on issues that we work through."

"I certainly don't have any concerns about that, about my brief absence from parliament and I won't be very far away, just good old Sandringham."

Ms Ardern said she was unsure how many hours she would work while on maternity leave but keeping across the issues was important to her.

"It is a little hard to quantify because I have said I will still receive Cabinet committee and Cabinet papers."

"I guess just to give you an indication, they trickle into me basically on a daily basis and I make my way through them through the course of the week and then on the weekend I get my Cabinet papers and that varies a little bit but I tend to have one of those double briefcases full of those each weekend."

"So it's a reasonable amount of reading but that's something I want to do to make sure that I continue keeping fully across the range of issues that we tackle."

"I do that when I'm away as well, so when I travel overseas I do the same thing."