The Constitution (One Hundred and Thirty-First Amendment) Bill, proposing one-third reservation for women in Lok Sabha and State Legislative Assemblies, failed to pass in Lok Sabha. The Bill required a special majority under Article 368 and ratification by half the State Legislatures as it amended the Constitution. Home Minister Amit Shah linked seat increases for SCs and STs to the delimitation exercise. The Bill's failure renews debate on Article 330 and reservation architecture under Part XV.

Women's reservation in Parliament is governed by Part XV (Articles 324–329) and requires a constitutional amendment under Article 368. The 131st Amendment Bill sought to insert a new provision reserving one-third of total seats — including seats already reserved for SCs and STs under Article 330 — for women in Lok Sabha and State Assemblies.

Article 368 classifies amendments into three categories: (1) simple majority, (2) special majority — two-thirds of members present and voting plus more than 50% of total membership of each House, and (3) special majority plus ratification by not less than half the State Legislatures. Amendments touching the representation of States in Parliament fall under category 3, making this Bill one of the most procedurally demanding.

The Bill's predecessor, the Constitution (81st Amendment) Bill 1996, lapsed multiple times across the 11th, 12th, and 13th Lok Sabhas. The Constitution (108th Amendment) Bill 2008 passed the Rajya Sabha in 2010 but lapsed on dissolution of the 15th Lok Sabha. The 106th Constitutional Amendment Act, 2023 (Women's Reservation Act) inserted Articles 330A and 332A but operationalised reservation only after the next delimitation exercise, creating a deferred commencement mechanism.

For CLAT PG, the critical doctrinal points are: the classification of amendment procedures under Article 368, the distinction between Articles 330 (SC/ST reservation) and 330A (women's reservation), and the role of delimitation under Article 82 as a precondition. For UPSC, the procedural sequence — Bill → special majority → State ratification → Presidential assent — is the dominant testing vector.