Nationals MP Advances Proposal to Define Sex in Law by Biological Criteria

Nationals MP Alison Penfold has introduced legislation to amend the Sex Discrimination Act that would define “man” and “woman” in law based on biological sex.

Member for Lyne Alison Penfold (L) speaks to Member for Canning Andrew Hastie (R) at Parliament House in Canberra, Australia, on Feb. 4, 2026. Hilary Wardhaugh/Getty Images

Clear gender definitions and protections for women-only spaces are back in federal parliament, with Nationals MP Alison Penfold introducing legislation to amend the Sex Discrimination Act.

The proposed amendment, introduced on May 25, seeks to define “man” and “woman” based on biological sex and strengthen legal protections for women-only spaces, services, and activities.