Chief Justice of India Dipak Misra on Wednesday asked whether the decision of the Lok Sabha Speaker to designate a bill as a money bill could be reviewed by the judiciary.

The question was posed to lawyers representing petitioners who have challenged the validity of Aadhaar, the 12-digit unique identification number. A five-judge Constitution bench began hearing the petitions on Wednesday.

The question came up when senior counsel Shyam Divan pointed to the amendments made to the Income Tax Act in 2017 through the introduction of the Section 139 AA, which made linking Permanent Account Numbers to Aadhaar mandatory. Divan said the money bill route was used in a manner not intended in the Constitution.

Justice Dipak Misra intervened, and posed the question. “Can courts review the decision of the Speaker to designate a bill as a money bill?” he asked. The Lok Sabha has the final say in passing a money bill as it has the right to decide on whether to accept or deny amendments proposed by Rajya Sabha.

Responding to the question, former Union Finance Minister P Chidambaram, who is appearing for one of the petitioners, said the Constitution was very clear in how the money bill should be used.

He said it was an instrument only for financial matters. He stressed on the word “only” in Article 110 of the Constitution, which defines the money bill. “If the bill violates Article 110, the judiciary has the power to review it for constitutionality,” Chidambaram said. It was only the members of the Lok Sabha who cannot question the Speaker’s decision, he argued.

Chidambaram also pointed to previous judgements that have elaborated on the importance of the Rajya Sabha. By clubbing amendments that had nothing to do with financial matters, the Rajya Sabha was rendered helpless, despite lawmakers raising strong questions.

When Divan said he would argue on the illegality of both the Aadhaar Act of 2016 and the various executive notifications that were used to sustain Aadhaar between 2009 and 2016 before the enactment of the law, Justice Misra pointed out that if the Act is held invalid, everything comes down. “When something violates the Constitution, it cannot stand,” he said.

On the petitioners’ apprehension that Aadhaar could be made mandatory for something like the mid-day meal scheme for school children, Justice DY Chandrachud pointed out that there could be a compelling state interest in ensuring that the benefits reached those who deserved it.

Justice Misra said the Centre’s argument could be that for the right to education guaranteed under the Constitution to be enforced. It was important to make sure that children actually came to school, he said.

He also briefly summed up the points Divan was making. The arguments against Aadhaar was founded on right to privacy, the question of Aadhaar being a tool of exclusion, and the unique identification number transgressing Constitutional ideals. When a regulatory provision “crosses the limit” and violates a fundamental right, it was a clear transgression, he said.