Teenagers wanting to have a civil union or de facto relationship will soon require approval from a judge.
Parliament is considering a bill in the name of National MP Joanne Hayes which is designed to protect 16 and 17 year-olds from forced marriage in New Zealand.
It will require them to get consent from a Family Court judge rather than their parents.
MPs on the Justice Committee have unanimously backed the bill after public hearings, and also decided to extend it to other legal relationships.
The committee's report said civil unions and de facto relationships provided many of the same legal protections as a marriage and including them in the legislation would avoid potential loopholes.