The Indian government is pushing back on an attempt by campaigners to win legal recognition for same-sex marriage, according to reports.

Officials have urged the court to reject challenges to the current legal framework lodged by LGBT couples, reported Reuters news agency, which has seen a Sunday filing submitted to the Supreme Court.

The Ministry of Law believes that while relationships in society may manifest in different forms, the legal recognition of marriage should be reserved for heterosexual relationships only, and the state has a legitimate interest in maintaining this.

“Living together as partners and having sexual relationship by same sex individuals … is not comparable with the Indian family unit concept of a husband, a wife and children,” the ministry argued in papers seen by the Reuters news agency but have not been made public.

The court cannot be asked “to change the entire legislative policy of the country deeply embedded in religious and societal norms”, it said.

India’s top court decriminalised homosexuality in a historic verdict in 2018 by scrapping a colonial-era ban on gay sex, following years of activism and lobbying.

The latest case is seen as an important milestone in the development of LGBT rights in India, home to 1.4 billion people.

The issue is still highly sensitive: speaking openly about homosexuality is still taboo for many in the socially conservative country.

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

Which other countries have legalised same-sex marriage?

Same-sex marriage is not recognised as widely in Asia as it is in the West.

Taiwan was the first in the region to recognise such matrimony, while other countries like Malaysia still criminalise same-sex acts.

Singapore last year ended a ban on gay sex but took steps to bar same-sex marriages.

Japan is the only country among the Group of Seven (G7) nations that does not legally recognise same-sex unions, although the public broadly favours recognition.

In India, the issue has fuelled tensions in the media and in parliament, where a member of Modi’s ruling Hindu nationalist party in December asked the government to strongly oppose the petitions filed in the top court.

LGBTQ+ activists argue that while the 2018 ruling affirmed their constitutional rights, it is unjust that they still miss out on legal backing for their marriages – a basic right enjoyed by heterosexual married couples.

“We can’t do so many things in the process of living together and building a life together,” one of the litigants in the current case, businessman Uday Raj Anand, told Reuters in December.

In Sunday’s filing, the government argued the 2018 ruling cannot mean recognising a fundamental legal right to same-sex marriage under the laws of the country.

The intent behind the current legal system on marriage “was limited to the recognition of a legal relationship of marriage between a man and a woman, represented as a husband and wife”.

The government has argued that changes to the legal structure should fall to the elected parliament, rather than the court.

The cases are due to be heard in the Supreme Court on Monday.

If India were to approve same-sex marriage, it would become the 33rd country to do so, according to Human Rights Campaign.