The Constitution (One Hundred and Thirty-First Amendment) Bill reserves one-third of seats for women in the Lok Sabha and state legislative assemblies. However, the reservation cannot take effect until after a delimitation exercise is completed following the first census conducted after the Bill's enactment. Home Minister Amit Shah noted that SC and ST seat counts will also increase with delimitation. The law is passed but its operation is deferred, making the delimitation timeline the critical legal trigger.

The 128th Constitutional Amendment Bill, passed by Parliament in September 2023 and subsequently renumbered, inserts Articles 330A and 332A into the Constitution, mandating one-third reservation for women in the Lok Sabha, state legislative assemblies, and the NCT of Delhi assembly. Crucially, it also carves out reservation for women within the existing SC and ST reserved categories.

The structural innovation — and the exam-critical tension — is the deferred commencement clause. The reservation does not activate upon Presidential assent. It activates only after: (1) the next Census is conducted following enactment, and (2) a fresh delimitation exercise is completed on the basis of that Census. Since the Census itself was delayed beyond 2021, the practical effect is that women's reservation in Parliament may not be operational until 2029 or later.

This creates a constitutionally novel situation: a fundamental rights-adjacent guarantee that is structurally contingent on executive action (conducting the Census) and a quasi-judicial process (the Delimitation Commission). Critics argue this makes the guarantee illusory; supporters say delimitation is necessary to ensure fair seat allocation before quotas apply.

For gender equality law, the amendment also raises questions about whether reservation within SC/ST categories creates an additional layer of intersectional protection — a concept the Supreme Court has engaged with in cases on affirmative action. The amendment does not provide reservation for OBC women, which was a significant political and legal debate during its passage.