The Supreme Court will on Tuesday begin to hear arguments on a batch of petitions that demand the scrapping of Section 377 of the Indian Penal Code.

Dating back to the 1800s, Section 377 criminalises anal and oral sex, referring to it as “unnatural sex”, and states that it is “against the order of nature with any man, woman or animal”. It also includes a maximum punishment of life imprisonment.

The court on Monday refused to adjourn the hearing after the Centre sought more time to file its response in the matter.

Chief Justice Dipak Misra reconstituted a Constitution bench last week to hear petitions on four matters, including Section 377, which criminalises “unnatural sex” even between consenting adults. The bench comprises Misra and Justices Rohinton Nariman, AM Khanwilkar, DY Chandrachud and Indu Malhotra.

The bench will hear six petitions and interventions filed by non-governmental organisation Naz Foundation, parents of queer people and Voices Against 377, a collective of human rights groups, reported Hindustan Times.

In 2009, the Delhi High Court read down Section 377 to decriminalise sexual activity between members of the same sex. However, in 2013, the Supreme Court set aside the order. The Supreme Court also placed the onus on Parliament, saying only it can scrap or change laws.

In August 2017, the Supreme Court ruled that the right to privacy is a fundamental right, that it is intrinsic to life and liberty. Sexual orientation, the court said in its judgment, is an “essential component of identity” and the rights of lesbian, gay, bisexual and transgender population are “real rights founded on sound constitutional doctrine”, according to NDTV.

On Sunday, the Indian Psychiatric Society said that homosexuality was not a psychiatric disorder. In an online statement, the society said it recognises “same sex sexuality as a normal variant of human sexuality much like heterosexuality and bisexuality.”