Transgender, gender diverse, and intersex people living in Victoria will now be able to apply to change the sex on their birth certificate and birth registration without having to undergo sex affirmation surgery.

Under new legislation introduced yesterday (the Births, Deaths and Marriages Registration Amendment Bill 2016) Victorian couples will no longer be forced to divorce if one partner wishes to change their gender identity. Previously, if one person in a marriage altered the gender recorded on their birth certificate, the couple would have to divorce as it would mean that they were in a same-sex marriage, which is currently illegal throughout Australia.

Adults will be free to apply for a change to their birth certificate and birth registration, and the legislation also introduces a mechanism for parents or guardians to apply on behalf of a child. Where the child is under 16, the application to change a child's gender identity must include a supporting statement from a doctor and psychologist stating that the child has capacity to consent to the change, and that the change is in their best interests.

Special Counsel Jodylee Bartal said that there may be unintended consequences flowing from good intentions. "Whilst the intention of the legislation is positive, under Australia's Marriage Act (Cth) if a person alters the gender on their birth certificate which results in a pre-existing marriage becoming a same-sex marriage, the marriage is not likely to be recognised as lawful in Australia.

"The Marriage Act defines marriage as "the union of a man and a woman to the exclusion of all others, voluntarily entered into for life". This definition at a federal level would suggest that if one person changes their gender under the Victorian legislation, although the couple will no longer be forced to divorce, their union may no longer be recognised as being "valid" for the purposes of the Marriage Act.

"This can have serious consequences if, for example, the couple eventually wishes to obtain a divorce. A divorce decree cannot be granted in Australia without the existence of a valid marriage. The practical effect of the Victorian legislation could be that couples are unable to get divorced if one person in the marriage changes their gender identity."