The National Party is questioning the affordability of making changes to paid parental leave following Labour's election proposal.
But Chris Hipkins says Labour's decision to phase in the proposed scheme was to "make it more affordable" and the party recognises "we are in a more constrained financial environment".
Labour on Tuesday announced that if it is re-elected at the October 14 election, it would create four weeks of 'paid partner's leave'. The partner of a primary carer could take four weeks of paid leave concurrently or consecutively with them in addition to the current two weeks unpaid leave offered.
The scheme would be phased in from July 2024. Initially, the partner would receive two weeks paid leave, and this would then increase to three weeks in July 2025 and four weeks by July 2026. That means the cost steadily increases, from $35m in 2024/25 to $75m in 2027/27 - an overall cost over the forecast period of $230m.
"As a dad who took leave when my kids were born, I know that was a decision I was incredibly fortunate to make," Hipkins said.
"This policy will help remove some of the financial barriers to partners taking parental leave. It supports all parents to be part of their babies’ youngest days, providing extra financial help when families need it most."
Reacting to the proposal on Tuesday, National leader Christopher Luxon said: "We would love to do it".
"We think it would be fantastic for New Zealand families and for New Zealand parents. The key issue is the affordability of it," he said.
"When you look at what is happening in the country at the moment, we are over-taxed. We have $73 billion worth of debt, we have deficits. It is really important we are prudent and responsible with taxpayers' money and that we can actually afford to do it."
Asked if parents should be a priority in a constrained economic environment, Luxon said: "Absolutely."
Luxon said National would have more to say with a families package expected to be released by the party prior to the election.
Hipkins said the decision to start with partners getting two weeks of paid leave and then scaling up to four by 2026 was "to make it more affordable".
He said he would have "of course" liked to have started with the full four weeks.
"But we have to recognise that at the moment we are in a more constrained financial environment."
National's deputy leader Nicola Willis said she "would love" partners to get paid leave and a Bill she introduced into the House would have allowed for that.
Willis' Bill would have allowed the primary carer to split their leave allowance, meaning the partner could stay at home at the same time as them.
She called it a "shameful day" when Labour voted it down earlier this month, arguing the governing part was choosing "politics over parents", especially as it came "at no extra cost to the taxpayer".
On Tuesday, she said there were several reasons why a partner may want to stay at home at the same time as the primary carer.
"I think often that is something that people need. Whether that is for reasons of the way the birth went, or because of physical reasons, or just because they need support. I would love that to be the case. We could have achieved with my Bill.
"There is then a second question of should we should be paying for more extensions to paid parental leave beyond the current entitlements… we would love to do that. What we need to look at is whether New Zealand can afford that."
Hipkins said Willis' Bill was "unimplementable."
"I have said we will do a fundamental review of the law itself and how the law itself operates to make sure we have got the flexibility built in that parents might be looking for."
Asked why Labour didn't support Willis' Bill to a Select Committee and have it fixed there, Hipkins said: "The first port of call should be aiming to increase entitlement rather than divvy up an existing entitlement."
He wouldn't rule out increasing flexibility.
Willis wouldn't say if there were any policies National has already announced that she would get rid of in order to pay for an extension to paid parental leave.
"We are very carefully putting together our policy manifesto based on our underlying commitment that we will manage the economy responsibly, to ensure that New Zealanders have good incomes, that we can get ahead, and that we can fund the public services so many people rely on."
That involves "a lot of balancing and a lot of calibration", Willis said.