A controversial new law allows men to be listed as mothers on birth certificates has passed parliament in South Australia despite warnings it defies biological reality.
The Deaths and Marriages Registration (Birth Certificates) Amendment Bill 2026 was introduced by Greens MP Robert Simms and supported by the Labor government, but opposed by One Nation and the Liberals.
The changes allow non-birth legal parents, who were previously listed as “other parent”, to choose between “mother”, “father” and “parent” if both parents agree. The laws also existing birth certificates to be altered.
A court is still determining how homosexual men who have been allowed to adopt children can be listed on birth certificates, meaning the changes will mainly affect lesbian couples.
But the Australian Christian Lobby warned the new law will enable “biological men to identify as a child’s mother” and “biological women to identify as a child’s father”, The Advertiser reported.
“Every child has a mother and a father. If our legal records are to maintain integrity and serve their legitimate purpose, they must reflect reality, not feelings,” ACL South Australia director Ashlyn Vice said.
Ms Vice accused the state government of “doubling down on gender ideology”, and said Australians were “increasingly weary of ideology overriding common sense, biological reality, and objective truth”.
One Nation opposed the bill on “biological reality” grounds, and state leader Cory Bernardi said “parent” should mean “someone who has brought forth or given birth to a new life”.
“The term co-parent is entirely accurate. It is entirely dignified. It does not demean any individual but acknowledges that in the creation of a child there is a father and a mother,” he said.
“If a same-sex couple is raising a child together, generally one is the father or the mother and the other is the co-parent. I do not think that demeans any relationship status.”
Mr Simms said the bill was a “positive step forward for LGBTI rights” and would be “welcomed by many rainbow families”.
“Same-sex parents in SA will now have more choice around how they are recognised on their children’s birth certificates after my Greens’ private members bill passed state parliament,” he said.
Header image: Mr Simms with supporters after the bill passed (Facebook).
