The bill is in the name of New Zealand First MP Jenny Marcroft.
Supporters of a bill seeking to legally define the terms "woman" and "man" say it is a matter of clarity, but opposition parties have described it as divisive and a "time warp".
The bill, in the name of New Zealand First MP Jenny Marcroft, passed its first reading in Parliament on Wednesday and will now go through the select committee process.
The Legislation (Definitions of Woman and Man) Amendment Bill would define "woman" in law as "an adult human biological female", and "man" as "an adult human biological male".
Marcroft said what it meant to be a woman was "under attack," and the bill would deliver clarity and consistency.
