Taiwan's legislature voted Friday to legalize same-sex marriage, a first in Asia and a boost for LGBT rights activists who had championed the cause for two decades.

Lawmakers pressured by LGBT groups as well as by church organizations opposed to the move approved most of a government-sponsored bill that recognizes same-sex marriages and gives couples many of the tax, insurance and child custody benefits available to male-female married couples.

That makes Taiwan the first place in Asia with a comprehensive law both allowing and laying out the terms of same-sex marriage.

The law does not bring full equality with heterosexual couples -- it only allows for biological adoption, for example, and marriages with foreigners are not recognized. But gay rights groups have said they were willing to accept compromises, as long as the new law recognized the concept of marriage, adding they could fight further legal battles over surrogacy and adoption down the line.

Taiwanese President Tsai Ing-wen, a supporter of the law, tweeted: "On May 17th, 2019 in Taiwan, LoveWon. We took a big step toward true equality, and made Taiwan a better country."

"It's a breakthrough, I have to say so," Shiau Hong-chi, professor of gender studies and communications management at Shih-Hsin University in Taiwan, told The Associated Press.

Thousands of people, including same-sex couples, demonstrated Friday morning in the rainy streets outside parliament before the vote, which took place on the International Day Against Homophobia, Transphobia and Biphobia. Many carried rainbow-colored placards reading "The vote cannot fail." About 50 opponents sat under a tent outside parliament and gave speeches favoring marriage between only men and women.

"For me the outcome today is not 100 percent perfect, but it's still pretty good for the gay community as it provides legal definition," Elias Tseng, a gay pastor who was among the crowds outside parliament, told AFP.

Victoria Hsu, a gay rights lawyer, said it was crucial that conservatives failed in their bid to delete the reference to marriage registration with lawmakers voting 66-27 in favor of the provision.

"In Taiwan a marriage will take effect when it's registered, so allowing marriage registration is no doubt recognizing the marriage itself," she told AFP.

Taiwan's Constitutional Court in May 2017 said the constitution allows same-sex marriages and gave parliament two years to adjust laws accordingly.

The court order mobilized LGBT advocacy groups pushing for fair treatment, as well as opponents among church groups and advocates of traditional Chinese family values that stress the importance of marriage and producing offspring.

Religion, conservative values and political systems that discourage LGBT activism have slowed momentum toward same-sex marriage in many Asian countries from Japan through much of Southeast Asia, although Thailand is exploring the legalization of same-sex civil partnerships.

"This will help spark a debate in Thailand, and hopefully will help Thailand move faster on our own partnership bill," said Wattana Keiangpa of the Asia Pacific Coalition on Male Sexual Health.

Phil Robertson, deputy Asia director for Human Rights Watch, said Taiwan's action should "sound a clarion call, kicking off a larger movement across Asia to ensure equality for LGBT people and pro-active protection of their rights by governments throughout the region. No more excuses!"

"We hope this landmark vote will generate waves across Asia and offer a much-needed boost in the struggle for equality for LGBTI people in the region," Annie Huang, from Amnesty International Taiwan, said in a statement.

Taiwan's acceptance of gay and lesbian relationships began in the 1990s when leaders in today's ruling Democratic Progressive Party championed the cause to help Taiwan stand out in Asia as an open society.

Although claimed by China as its own territory, Taiwan is a self-governing democracy with a vibrant civil society dedicated to promoting rights for sexual and ethnic minorities, women, the handicapped and others.

In the last decade, Taiwan has been one of the most progressive societies in Asia when it comes to gay rights, staging the continent's biggest annual gay pride parade.

But the island remains a staunchly conservative place, especially outside urban areas.

In November 2018, a majority of Taiwan voters rejected same-sex marriage in an advisory referendum. However, legislators favoring the bill, and voting separately on each item largely along party lines, said it followed the law as well as the spirit of the referendum.

"We need to take responsibility for the referendum last year and we need to take responsibility for people who have suffered from incomplete laws or faced discrimination," ruling party legislator Hsiao Bi-khim said during the three-hour parliament session.

However, voters comprehensively rejected defining marriage as anything other than a union between a man and a woman, illustrating the limited popular support for change.

Tsai had previously spoken in favor of gay marriage but was later accused of dragging her feet after the court judgement, fearful of a voter backlash.

Taiwan goes to the polls in January and the gay marriage issue could hamper Tsai's chances of re-election.

Opponents were incensed by the vote, saying the inclusion of the "marriage registration" clause ignored the 70 percent of voters who had cast ballots in the referendum wanting to keep marriage limited to a man and a woman.

Opponents also raised fears of incest, insurance scams and children confused by having two mothers or two fathers. Both sides of the issue have held colorful street demonstrations and lobbied lawmakers.

"This is going to cause a lot of morality problems," said Lin Shih-min with the Taiwan political action group Stability of Power, which opposed the law. "From the point of view of the children, they have the right to grow up with both a mother and a father."

Tseng Hsien-ying, from the Coalition for the Happiness of Our Next Generation, told local media the vote "trampled on Taiwanese people's expectations that a marriage and a family is formed by a man and a woman, a husband and a wife."

Mainland China, ruled by the authoritarian Communist Party, remains much more conservative and officials have repeatedly discouraged even the discussion of legalizing same-sex marriage.

Despite that, news of Taiwan's new law was a major trending topic on social media in China, with more than 100 million views on the Twitter-like microblogging site Weibo.

At least 20 same-sex couples are planning a mass marriage registration in Taipei on May 24, a spokesman for the advocacy group Marriage Equality Coalition Taiwan said. The newlyweds and hundreds of invitees will hold a mass party a day later on a blocked-off boulevard outside the presidential office, the event organizer said.

The law will give a boost to Jay Lin and his partner, who hope to marry and assume joint custody of their two 2-year-old sons. They plan to register after May 24.

"A lot of gay parents are excited about that already," said Lin, a Taipei-based online streaming service founder.

"I think once more people are married and more families are more comfortable being out in public, that will naturally have a beneficial impact on society and on people's minds," Lin said.

Australia and New Zealand are the only places in the wider Asia-Pacific region to have passed gay marriage laws.

Vietnam decriminalized gay marriage celebrations in 2015, but it stopped short of full legal recognition for same-sex unions.