Taipei: Taiwan's parliament began debating Asia's first gay marriage law on Friday as conservative lawmakers launched a last-ditch attempt to scupper the most progressive bill in favour of a watered-down "civil-union" law. Hundreds of gay rights supporters gathered despite heavy rain near Taipei's parliament as a mammoth legislative debate got under way over an issue that has bitterly divided the island. Parliament is up against a ticking clock. Taiwan's top court has ruled that not allowing same-sex couples to marry violates the constitution. Judges gave the government until May 24 this year to make the changes or see marriage equality enacted automatically. But they gave no guidance on how to do that. With that deadline fast approaching, three bills have been tabled for Friday's vote -- which also happens to be the International Day Against Homophobia, Transphobia and Biphobia.

The most progressive is the government's bill, the only one to use the word "marriage" and to offer limited adoption rights. It is backed -- begrudgingly -- by gay rights groups who see it as the closest thing to full equality with heterosexual couples, despite its limitations. Opponents have tabled two other versions which avoid the word marriage, offering something closer to same-sex unions with no adoption rights. Conservative and religious groups have been buoyed by a series of referendum wins in November, in which voters comprehensively rejected defining marriage as anything other than a union between a man and a woman. In a Facebook post President Tsai Ing-wen said she recognised the issue had divided "families, generations and even inside religious groups". But she said the government's bill was the only one that respects both the court judgement and the referendum. "Today, we have a chance to make history and show the world that progressive values can take root in an East Asian society," she added in a tweet.