NEW DELHI - India's Supreme Court on Monday said a five-judge bench will start hearing final arguments over granting legal recognition to same-sex marriages on April 18, proceedings of which will be live-streamed on its website and Youtube.

The case is being seen as a milestone event for LGBT rights in the country. India's top court decriminalised homosexuality in 2018 by scrapping a colonial-era ban on gay sex.

But the government said it opposes recognising same-sex marriage and urged the Supreme Court to reject challenges to the current legal framework lodged by LGBT couples.

"When the question of granting recognition, legal sanction to a relationship is concerned, that is essentially a function of the legislature and for more than one reason," India's Solicitor General Tushar Mehta, arguing on behalf of the government, told the court.

"The parliament will have to debate and take a call whether in the view of societal ethos and several other factors which go into lawmaking, whether we would like this institution to be recognised."

In recent months at least 15 pleas, some by gay couples, have been filed asking the court to recognise same-sex marriages, setting the stage for a legal face-off with Prime Minister Narendra Modi's government.

The issue of same-sex marriage is sensitive in India and speaking openly about homosexuality is taboo for many in the socially-conservative country of 1.4 billion people.

LGBT activists say that while the 2018 ruling affirmed their constitutional rights, it is unjust that they still lack legal backing for their unions, a basic right enjoyed by heterosexual married couples.

"We are of the considered view that it would be appropriate that the issues raised are resolved by a bench of five judges of this court," Chief Justice of India D.Y. Chandrachud said while dictating the order.

(Writing by Sudipto Ganguly; editing by Angus MacSwan)