Government lawyers warned on Monday that granting spousal benefits to gay couples married overseas would amount to legalising same-sex marriage and “open flood gates” at an appeal case, according to the South China Morning Post (SCMP).

Senior immigration officer Angus Leung Chun-kwong lodged a judicial challenge after his same-sex partner Scott Adams was refused spousal benefits, and a lower court ruled in his favour before the government launched an appeal.

Representing the government, Barrister Monica Carss-Frisk QC said the preferential treatment of heterosexual married couples was justified by the potential flood of legal challenges by same-sex couples who married overseas, according to the SCMP.

Karon Monaghan QC, for Leung, argued that it was only reasonable to recognise the union.

High Court chief judge Andrew Cheung Kui-nung reportedly said the matter was a policy decision and said “bow we are in the 21st century,” acknowledging that the policy was introduced when homosexual acts were still illegal.