NEW DELHI: India's top court is set to rule on Thursday on whether to scrap a colonial-era ban on homosexuality that it reinstated in 2013 after four years of decriminalisation, in a landmark judgement that activists hope will uphold the right to equality.

Gay sex is considered taboo by many in socially conservative India, and despite opposition to lifting the ban from some lawmakers, activists are hopeful the Supreme Court will throw it out.

"The mood is extremely optimistic: the judges have been extremely empathetic," said Akhilesh Godi, one of the petitioners in the case. "It is not only about decriminalising but recognising our fundamental rights."

Anwesh Pokkuluri, a second petitioner, said: "Based on how the proceedings have gone, we do not see how they can uphold (the ban)."

The judges in the case had previously said that gay people in India face deep-rooted trauma and live in fear.

The homosexuality law, commonly known as "Section 377", prohibits "carnal intercourse against the order of nature with any man, woman or animal" - which is widely interpreted to refer to homosexual sex.

Gay sex is punishable by up to 10 years in jail.