The Lok Sabha on Wednesday passed the Aadhaar Bill soon after the Rajya Sabha returned it with several amendments. The Lok Sabha, however, rejected the amendments to the Bill, which seeks to govern the use of the Unique Identification Number to target specific subsidies, and passed it in its original form. The Congress walked out in protest. Earlier, members of the Bahujan Samaj Party, Trinamool Congress and Biju Janata Dal had walked out of the Rajya Sabha while raising several objections.

During the discussion on the Bill in the Upper House, the Opposition had attacked the government for passing the Aadhaar Bill as a Money Bill in the Lok Sabha last week, and also reiterated concerns that it would impinge on citizens' privacy. While Communist Party of India (Marxist) General Secretary Sitaram Yechury questioned the competence of the House while the Supreme Court was also considering the issue, senior Congress leader Jairam Ramesh moved a few amendments to the Bill and asked for it to be referred to a select committee.

Money Bills, which are specifically concerned with the way the government spends its funds, can only be introduced and passed in the Lok Sabha. The Rajya Sabha, where the Bharatiya Janata Party does not have a majority, can suggest changes to it.

Defending the government’s move, Finance Minister Arun Jaitley argued that since the Aadhaar Bill is directly related to providing subsidies and services, it qualifies as a Money Bill. He said, "If the principle purpose [of a Money Bill] is money spent out of the consolidated fund of India in a particular manner and the machinery [in this case Aadhaar] is created for spending that money, the machinery is an incidental vehicle, therefore it is a Money Bill."

Jaitley also clarified the privacy concerns, saying this aspect has been tightened in the law. However, Jaitley added that privacy is not an absolute right and can be restricted through legal procedure. He insisted that the Bill in its present form is vastly different from the one formulated by the last United Progressive Alliance government, especially on the privacy front.

The Bill has been widely criticised for its vulnerability to misuse. Jaitley said the UPA's Bill did not mention the purpose for the information gathered through the Unique Identification Number project, or state how this information would be used. However, the National Democratic Alliance government has plugged these holes, he insisted. The sole purpose of the Bill is to ensure that subsidies reach those who need it, he added.

According to Article 110 of the Constitution, a Money Bill passed by the Lower House must be discussed in the upper House within 14 days of it being tabled, after which it is considered passed by default.