NEW DELHI (AFP) - Hundreds of gay and lesbian Indians will take to the streets of New Delhi on Sunday, demanding equal rights and a reversal of the recent ban on gay sex as the country celebrates its Republic Day.

Members of various rights groups and civil society activists will also join the protest march that will kick off in the heart of the city's business district after the Republic Day celebrations wind up.

"We want to ask the government if we are included in India's current idea of a republic," said Mohnish Malhotra, one of the organisers of the parade.

"The government has failed in its constitutional duty to protect and advance gay rights," he added.

Gay sex had been effectively legalised in 2009 when the Delhi High Court ruled that a section of the penal code prohibiting "carnal intercourse against the order of nature" was an infringement of fundamental rights.

But last month, India's apex court ruled that the High Court had overstepped its authority and that a law passed in the 1860s during British colonial rule was still valid.

Criminal prosecutions were rare when the law was previously in force, but police used it to harass people and demand bribes.

The ruling was met with dismay by gay rights activists who called it a "Black Day" for India and criticised the government for leaving such an important issue in the hands of the courts rather than address it through legislation.

Gay sex has long been a taboo subject in conservative India but in recent years the community has raised its profile through gay pride marches, magazines and events which have encouraged many to come out of the closet.

Mr Malhotra said the Republic Day presented an ideal opportunity for the community to "reclaim" their rights.

The Republic Day is celebrated annually with a colourful military parade at the iconic India Gate in the capital, complete with missiles, tanks and march pasts by uniformed soldiers.

The national holiday marks the day when the Indian Constitution came into force in 1950.

"As we commemorate another Republic Day, we proclaim that the parade of the powerful does not represent us. We demand that our government be held accountable for the protection of our rights according to our constitution," Mr Malhotra said.