The top court's approval for a transsexual to wed has sparked widespread fears in the Catholic Church, which sees the ruling as opening the door to same-sex marriage in Hong Kong.
Reverend Dominic Chan Chi-ming, the vicar-general of the Catholic Diocese, said he was concerned about the possibility of de facto same-sex marriage. Chan's remarks came as the church's publication, Kung Kao Po, in its latest issue yesterday warned that the court's ruling may "clash with the established concept of marriage".
Chan said: "What if a man and a woman get married and then one of them undergoes sex-change surgery? Is that same-sex marriage?"
Chan stressed that the church would stand firm on "one man, one woman" marriages - a pattern he said was "internationally recognised and upheld beyond the Catholic Church".
He said he respected the court ruling, but added that legal principles - though solely relied on by the judiciary - did not exhaustively cover all aspects of society.
"There are social ethics and public interest to consider as well," Chan said.
He was speaking for the first time since the Court of Final Appeal's decision last Monday, ruling in favour of a transsexual woman known as "W".
It held that provisions in the Marriage Ordinance and the Matrimonial Causes Ordinance must include a "post-operative male-to-female transsexual person" within the meaning of "woman" and "female". But it suspended the order for a year so the legislature could decide if new laws are needed.
Michael Vidler, the solicitor for W, had said the latest decision had no impact on the development of gay marriage because it dealt with gender identity rather than sexual orientation.
In yesterday's issue, Kung Kao Po said some members in the church "fear changes to marital concepts" in the wake of the judgment.
Quoting Kevin Lai Yuk-ching, executive secretary of the Diocesan Pastoral Commission for Marriage and the Family, the article said: "The laws of ethics and nature emphasise that [one's] gender is inborn; it cannot be altered after birth."
Lai was also quoted as saying: "Procreation and sex are inseparable ... the legal standard will change the social perceptions in the long run. While quite a number of overseas places have amended the laws to allow transsexuals to marry ... the communities should not rely solely on consensus or focus on rights, but should give consideration to the nature of gender and the impact to families."
Raymond Chan Chi-chuen, the openly gay lawmaker of People Power, described the church's approach to minority rights as outdated.
"My view is that the decision actually strengthens the marriage concept between a man and a woman," Chan said. "It clarifies who is a woman."
Chan said the spirit of the judgment was "not about the minority succumbing to the majority, but the majority respecting the minority".