They contended that the collection of biometric data and iris scan violated the fundamental right to privacy as personal data was not protected, and was vulnerable to exposure and misuse.
On June 10, the Supreme Court had ruled that from July 1 onward, every person eligible to obtain Aadhaar card must quote their Aadhaar number or their Aadhaar Enrolment ID number for filing of Income Tax Returns as well as for applications for Permanent Account Number (PAN).
Requesting an early hearing, the Centre on Wednesday had said, "Millions of people are involved in the outcome of the case".
When Justice Khehar asked Venugopal and Divan whether the matter should be heard by a larger Constitution Bench, both the parties said it has to be first heard by a five-judge bench.
It was argued that Aadhaar card is an invasion of privacy and a bad violation of basic human rights.
The court clarified that this Bench will take into consideration the decisions of the 8 judge Bench, and a nine judge Bench will be set up, if required.
The five-judge bench will hear the concerns over privacy implications of mandating Aadhar card.
A Bench led by Justice A.K. Sikri had in February referred the appeals to the Chief Justice to constitute a Constitution Bench of the appropriate number of judges. Sinha is the former NCPCR chairperson and Magsaysay victor.