Prime Minister Jacinda Ardern has announced a list of expectations Deputy Prime Minister Winston Peters must fulfil when he steps in as Acting Prime Minister.
That's expected to be in mid-June, when Ms Ardern takes leave for six weeks after she gives birth.
Mr Peters and Ms Ardern were quick to defend the letter when asked whether it was a "behave-yourself contract".
"The reality is I was doing this job 22 years ago, so I'm ready for it," Mr Peters said.
"The Prime Minister and I crafted this together, and in the last six months that's exactly what we've done.
"We've worked co-operatively, and anyone who says otherwise, to use Geoffrey Palmer's favourite phrase, is spreading rumour with malice."
As for the timing of the letter - a full month before Ms Ardern's due date - the Prime Minister said she's not expecting to have to take maternity leave early, "but one should always be prepared".
During her leave, she will be in contact with Mr Peters about any "significant matters", and will still be receiving papers.
Ms Ardern said she sees the arrangement as no different to the current procedures that happen in the coalition Government.
"This is a letter that simply sets out our usual day-to-day way of working anyway," she said.
Asked what would happen if Mr Peters didn't live up to expectations, Ms Ardern said: "I do not have that concern for a moment."
Mr Peters has no international travel planned during the six-week period. In the event that he needed to leave the country, Labour deputy leader Kelvin Davis would take over as Acting Prime Minister.
Mr Peters responsibilities as Acting Prime Minister include:
- Chairing Cabinet and the Cabinet committees usually chaired by the Prime Minister
- (Appointments and Honours Committee, Cabinet Business Committee and Cabinet Priorities Committee)
- Engaging with and directing officials from the Department of the Prime
- Minister and Cabinet
- Overseeing the government's policy programme;
- Answering questions directed at the Prime Minister in the House and responding to media inquiries, Official Information Act requests and other correspondence
- Attending official engagements
Mr Peters will also take over Ms Ardern's security and intelligence portfolios, which she says have "significant crossover with the role [he] already holds".
Ms Ardern said the only real difference would be a change to the frequency of briefings that he already receives.