The Victorian parliament has voted to outlaw gay conversion therapy in a marathon sitting of the state's upper house.
The "world-leading" Change or Suppression (Conversion) Practices Prohibition Bill passed the Legislative Council late on Thursday night 29 votes to nine following a 12-hour debate.
Liberal MPs Bev McArthur and Bernie Finn broke party ranks and voted against the government's legislation, along with crossbench MPs Jeff Bourman, Catherine Cumming, Clifford Hayes, Stuart Grimley, David Limbrick, Tania Maxwell and Tim Quilty.
The bill outlaws any therapy that attempts to change or suppress a person's sexual orientation or gender identity and empowers the Victorian Equal Opportunity and Human Rights Commission to investigate reports of conversion practices.
It also puts in place strong criminal sanctions for people who subject others to conversion practices that cause injury or serious injury, with up to 10 years' jail for the latter.
Those who try to get around the laws by sending people to conversion practices out of the state would also face criminal sanctions and fines to a maximum of almost $10,000.
LGBTIQ+ advocates have welcomed the legislation, describing it as "life-saving".
“We were delighted to see cross-party support in the Victorian Parliament for this life-saving legislation," CEO of Equality Australia Anna Brown said.
"While no law can fix a complex social problem on its own, this law is a great step towards ending the incredible harm caused by LGBTQ+ conversion practices and paves the way for positive reform in other parts of Australia.
“This law sends a powerful message that LGBTQ+ people are whole and valid just as they are, and establishes powerful mechanisms to deal with incredibly harmful practices that LGBTQ+ people have, for too long, endured across Victoria.”
Nathan Despott from advocacy group Brave Network credited the work of survivors of conversion therapy to make the legislation a reality, stating the "ground work often involved painfully sharing our stories and insights repeatedly over several years".
"These legislative changes have been hard-won, with survivors of conversion practices re-living their trauma in order to secure passage of this world-leading legislation," he said.
The bill was all but guaranteed to pass after Reason Party MP Fiona Patten, Samantha Ratnam of the Greens and Andy Meddick from the Animal Justice Party confirmed on Tuesday they would back the Change or Suppression (Conversion) Practices Prohibition Bill in the Legislative Council.
In supporting the bill, Mr Meddick described himself as the proud father of two "perfect" transgender children.
"They do not need fixing, nor do any other children or adults who do not fit an often religiously held belief that sexuality and gender are binary only," he said.
Labor's Harriet Shing, the first openly lesbian member of Victorian Parliament, acknowledged conversion therapy victims and survivor groups who have been advocating for the ban for years.
"[Their experiences] have had the effect, directly or indirectly, of breaking them or trying to break them," she said.
Ms Shing called out the "cognitive dissonance" and "doublespeak" of MPS who were opposing the bill despite supporting a ban on conversion practices.
"It is not acceptable that in a debate like this victims and survivors and our communities, my communities, are denied the opportunity to have our equality, our pain and hurt and trauma, on a footing which is of the utmost importance," she said.
The bill passed the lower house of parliament in December last year with 55 MPs voting in favour of the bill and the Liberal opposition abstaining.
Earlier on Thursday, some Liberal MPs tried to withdraw the bill for further consultation, but there were defeated narrowly by a vote.
The bill goes further than a similar law passed in Queensland in 2020, by prohibiting harmful practices not only in healthcare settings but also in religious settings.
It bans "carrying out a religious practice including but not limited to, a prayer based practice, a deliverance practice or an exorcism".
Faith groups have claimed the bill attacks religious freedom, while some medical professionals have raised concerns it could compromise the practice of psychiatry and psychotherapy.
"This bill does not outlaw prayer. It does not prevent health professionals from doing their job. It does not stop parents from talking to their kids about their views about sexuality or gender," Attorney-General Jaclyn Symes said.
"To suggest anything to the contrary is rubbish."
Ms Symes, who replaced Jill Hennessy in the role in December, said she was "friggin' proud" to be carrying on her predecessor's work.
"I can't wait to go home and tell my kids what I did today," she said.
The legislation will now go to the Victorian governor for royal assent. It will not come into effect for 12 months.
With AAP.
LGBTIQ+ Australians seeking support with mental health can contact QLife on 1800 184 527 or visit . also has a list of support services.
