The court referred a related debate over whether privacy is a fundamental right to a constitution bench
Whether the Aadhaar card can be used for services like opening bank accounts and taking phone connections will be decided by the Supreme Court today.
The government's ambitious unique identity or UID programme has been challenged in court over privacy concerns since it uses biometric data like fingerprint and iris scans.
The top court has already ruled that Aadhaar card can be used only for availing subsidies under the public distribution system and purchasing kerosene and cooking gas and that, too, voluntarily.
The court has also referred a related debate over whether privacy is a fundamental right to a constitution bench.
After a slew of blows to the UID scheme, the Centre, Reserve Bank of India, stock market watchdog SEBI, telecom regulator TRAI, and a number of states moved the Supreme Court for extending the voluntary use of Aadhaar card to other services.
In a two-hour-long hearing on Tuesday, high drama unfolded in court with heated exchanges between Attorney General Mukul Rohatgi, representing the Centre, and challenged by lawyer Shyam Diwan.
The Attorney General argued that when people are prepared to forgo the right to privacy for availing a "larger benefit" why should court "stand in the way?"
Representing petitioners Justice KS Puttaswamy and an NGO, Nagarik Chetna Manch, lawyer Shyam Diwan argued that Right to Privacy, whether it is for the poor or the illiterate, is "sacrosanct and can't be compromised".
Mr Rohatgi claimed around Rs 14,000 crore was saved by the government exchequer in one year by using the Aadhaar card and flushing out bogus beneficiaries for subsidies.
Petitioners opposing Aadhaar argued that since there was no law on forsaking privacy of citizens and the debate had been referred to a larger panel, this bench of three judges should not hear it.
Countering this, the Attorney General said, "We don't know when the larger bench will be constituted. It may take few months and till such time, should citizens wait? This court opened its doors at 2 am for an individual, can the court shut for crores of people?"
TRAI asserted that since the mandatory use of the Aadhaar card had been stopped by the Supreme Court, it was now "easy" for terrorists to get mobile connections.
Once the hearing concluded, the Court said it will pass orders at 3:30 pm on Wednesday.