National has doubled down on its attempt allow parents to take parental leave at the same time.
National Party Workplace Relations spokesperson Amy Adams will introduce a Private Member's Bill that would amend Paid Parental Leave (PPL) legislation currently before the House.
The Government's legislation will extend PPL from 18 to 26 weeks and is likely to pass with support from National.
During the campaign, National called for shared parental leave and now Ms Adams is challenging the Government to adopt the policy itself.
Last week, Prime Minister Jacinda Ardern told Newshub she liked National's proposed amendment, but there would be issues to work through, so it couldn't be put through under urgency along with the rest of the Bill.
"There is a really good chance that we're going to progress this, but I've just got to do my job and do it properly," Ms Ardern said.
"If we just put it through [under] urgency and suddenly a business says to me, 'Well, actually, now you're making me cover for two employees and that's going to be tough'."
Putting a Bill through urgency means it skips public submissions and the ironing out process of a select committee. In its current form, the Bill has already been through select committee, but was vetoed by the National Government on financial grounds.
The Government says it doesn't need to go through select committee again, but because it's not going through select committee, National's amendment can't be added.
If it's tabled as a Private Member's Bill, though, it can go through select committee without the rest of the Bill.
Ms Adam is likely to seek leave to table her Bill. If she has consensus from the House, it can be debated.
If the amendment is opposed by just one member of the House, it would be consigned to the biscuit tin, along with all the other members' Bills.