One of National's senior MPs would support taking abortion out of the Crimes Act.
Nikki Kaye, National's Education Spokesperson, told Newshub the current law is "archaic" and if a Bill came before Parliament, she would vote for change.
"I've been really open about the fact that I think the law's pretty archaic," Ms Kaye said.
"This stuff is typically a conscience issue, and if a bill came before Parliament, I'd vote for change. That's just how I personally view the issue."
The comments came during a Facebook live with Newshub, in which she also spoke about dealing with cancer, her love for Great Barrier Island - which is part of her Auckland Central electorate - and spoke in defence of Finance Spokesperson Steven Joyce's claim of an $11.7b hole in Labour's fiscals, an assertion widely rejected by economists.
Ms Kaye's stance puts her in direct opposition to her leader on the issue, and on-side with Labour Leader Jacinda Ardern, but it's likely to be an issue politicians are divided on within both parties. As a conscience vote, they would be able to cast a vote as they see fit rather than voting as a unified party.
The issue was raised during the Leaders Debate on Monday.
Ms Ardern said she would take abortion out of the Crimes Act. National leader Bill English, a devout Catholic, said he would leave the law as is.
"I do support the law as it stands. It is rightly a conscience issue for Parliament. We would not make it a party political issue, but if the changes came before the Parliament, I'd be opposed to liberalising the law," Mr English said.
"It seems to operate in a day-to-day way that is broadly satisfactory, and so I support the current law."
On Tuesday, Ms Ardern told media if elected to Government, Labour would involve the Abortion Supervisory Committee and the Ministry of Health in drafting a law change.
"They know which elements aren't working. I've already heard them present at Select Committee saying that they know there are changes that are required to the law because it's not fit for purpose and it needs to be modernised."
Ms Ardern said a Bill would be drafted allowing members of Parliament to vote on elements they agree with.
Law in New Zealand says abortion is legal before 20 weeks' gestation if two doctors deem the pregnancy "a risk to the physical or mental health of the mother". Women of any age can consent to or refuse an abortion.
Women can obtain an abortion at under 20 weeks' gestation under the following scenarios:
- if the pregnancy is a risk to the physical or mental health of the mother
- if there's a substantial risk that the child would be "seriously handicapped"
- if the child is a result of incest
- if the woman is "severely subnormal"
Other factors that may be taken into consideration include extremes of age and sexual violation.
After 20 weeks' abortions may be performed to save the life of the mother or to prevent serious mental or physical damage to the mother. After 20 weeks foetal abnormality in itself is not a ground for abortion.