The right to privacy "is protected as an intrinsic part of Article 21 that protects life and liberty," the Supreme Court ruled. The government insisted it had not lost its case. Law Minister Ravi Shankar Prasad claimed that judges have agreed that "privacy as a fundamental right is subject to reasonable restrictions." Today's verdict comprised of six different judgements, though they all concurred on privacy as an intrinsic right.

The Supreme Court order is based on an array of petitions that have challenged the mandatory use of Aadhaar cards which assign a unique 12-digit ID to every citizen. The Aadhaar database links iris scans and fingerprints to more than a billion people.

Today's verdict does not comment on whether the government's demand for Aadhaar to be linked to all financial transactions amounts to an infringement of privacy. The opposition led by the Congress said that the government's intent of "suppression through surveillance" has been defeated by the Supreme Court.

Whether Aadhaar can be made mandatory as the government insists for all financial transactions and for benefits of welfare schemes will be decided by a separate and smaller bench of the Supreme Court. But experts said that today's ruling could prompt the government to tweak its arguments in that case. The Supreme Court dismantled key claims made by the government, stating, "The refrain that the poor need no civil and political rights and are concerned only with economic well-being has been utilised through history to wreak the most egregious violations of human rights". It added, "The poor (the Attorney General) talks about today have cell phones, and would come forward to press the fundamental right of privacy."

All fundamental rights come with reasonable restrictions, said noted lawyer Prashant Bhushan. Whether Aadhaar can be seen as a reasonable restriction has yet to be decided, he cautioned.

In May, then Attorney General Mukul Rohatgi rejected suggestions that Indians could refuse to provide their iris scans or fingerprints to the government, telling a court "the concept of absolute right over one's body was a myth".

The petitioners in today's case had stressed that the Aadhaar database was originally presented as a purely voluntary programme that offered to provide every Indian with an identity card.

The government says Aadhaar is essential for all services including tax returns, opening bank accounts and securing loans, pensions and cash transfers for those entitled to welfare schemes. It has rejected suggestions that the Aadhaar programme, set up in 2009 by the previous Congress-led government, poses a threat to civil liberties.

Critics say the Aadhaar identity card links enough data to allow profiling because it creates a comprehensive profile of a person's spending habits, their friends and acquaintances, the property they own, and a trove of other information.