The Constitution (131st Amendment) Bill, 2026, which sought to restructure delimitation of parliamentary constituencies, was defeated on the floor of the Lok Sabha — the first constitutional amendment bill brought by the current Union Government to fail there. It could not secure the mandatory two-thirds majority of members present and voting, as required under Article 368. The defeat marks a significant parliamentary moment and raises fresh questions about the constitutional mechanics of amending delimitation provisions.

Article 368 of the Constitution lays down the procedure for constitutional amendments. A constitutional amendment bill must be passed in each House of Parliament by a special majority — a majority of the total membership of that House AND a majority of not less than two-thirds of members present and voting. The 131st Amendment Bill's defeat in Lok Sabha is exam-critical because it tests aspirants on the exact mechanics of Article 368 and the distinction between ordinary bills (simple majority), constitutional amendment bills (special majority), and certain amendments that additionally require ratification by at least half the State Legislatures (e.g., those affecting federal provisions like Article 368 itself, the representation of States in Parliament, Articles 54, 55, 73, 162, etc.).

Delimitation — the redrawing of constituency boundaries — is governed by Article 82 (after each census) and Article 170 (for State Assemblies). A Delimitation Commission is constituted under the Delimitation Act. There have been four Delimitation Commissions: 1952, 1963, 1973, and 2002 (whose orders came into effect in 2008). The current controversy centres on whether delimitation post-2026 (after the 2021 census) should be conducted and whether representation of southern States, which have better implemented population control policies, should be protected.

The failure of this bill is constitutionally significant because it is the first instance of a government-brought constitutional amendment bill falling in Lok Sabha, testing the structural safeguard that Article 368's supermajority requirement provides against majoritarian overreach.