Hong Kong's highest court on Monday began hearing the final appeal of a transsexual woman who is seeking to wed her boyfriend, in a potentially groundbreaking case for the Chinese city.
The woman, who was born as a man, is known only as "W" under anonymity rules and is now in her 30s. She is seeking to overturn earlier verdicts that said marriage is only allowed between couples who were of the opposite sex at birth.
W, who launched her legal battle in 2010, argues those rulings were a violation of her constitutional rights as her gender is recognised on other legal documents and her re-assignment surgery was government-subsidised.
The city's Registrar of Marriages had said that she could not marry her boyfriend because her birth certificate -- which cannot be changed under Hong Kong law -- said she was male.
"We say the laws of marriage can and should recognise that sexual identity can change," W's counsel David Pannick told the Court of Final Appeal in his opening arguments at the two-day hearing.
"The right to marry is fundamental... the birth certificate is a record of historical facts," he said, adding that W is now "medically, psychologically and socially" a woman.
The lawyer said the Registrar of Marriages should recognise his client's new gender, which is stated in official documents like her identity card and passport.
W was not present in court on Monday.
The government lawyers will put forward their submissions later. They have previously argued that existing laws did not accommodate transsexual marriage, and that any attempt to reinterpret the definition of "man" and "woman" would create uncertainties in the law.
W is one of a few people to have undergone sex reassignment surgery in Hong Kong. Official figures showed between 2008 and 2012, 16 such operations were conducted at public hospitals, but many others are believed to have travelled overseas for the procedure.
Activists say the case highlights the lack of legal protection and widespread discrimination faced by the sexual minority group in the modern Asian financial hub.
The city's gay community has also pushed for the recognition of same-sex marriage, which is not legal in Hong Kong.
"Why should we put them in such limbo when the sex reassignment surgeries were sponsored and approved by the government?" Hong Kong Human Rights Monitor director Law Yuk-kai told AFP.
"Most jurisdictions have recognised their acquired gender and ensure they will be able to lead their way of life including the right to have a family."
W's lawyer argued that many countries have allowed transsexual people to marry the opposite sex in their new gender, including mainland China since 2004, as well as Japan and Australia.
In rejecting W's case in 2010, a lower court said there was insufficient evidence "to demonstrate a shifted societal consensus in present-day Hong Kong regarding marriage to encompass a post-operative transsexual".