Delimitation of Constituencies

Delimitation of constituencies is the constitutional process of redrawing the boundaries of territorial constituencies for the Lok Sabha and State Legislative Assemblies, and of re-determining the number of seats reserved for Scheduled Castes and Scheduled Tribes, so that representation keeps pace with population change. It is carried out by an independent Delimitation Commission acting under a law made by Parliament, not by the government of the day.

Constitutional Basis

Article 82 directs that upon completion of each census, the allocation of Lok Sabha seats among the States and the division of each State into territorial constituencies "shall be readjusted by such authority and in such manner as Parliament may by law determine." A proviso protects continuity of representation: any readjustment does not disturb existing representation until the sitting House is dissolved. A further proviso lets the President notify the date from which a readjustment takes effect, so elections can continue on the old constituencies until then.

Article 170 applies the same readjustment principle to State Legislative Assemblies, while Articles 330 and 332 require the number of seats reserved for Scheduled Castes and Scheduled Tribes in the Lok Sabha and Assemblies to be re-fixed on the same census basis. Together, Articles 81, 82, 170, 330 and 332 form the constitutional core of the delimitation exercise.

Delimitation Commissions Constituted So Far

Parliament has set up a Delimitation Commission on four occasions, each time through a dedicated Act:

The Fourth Delimitation Commission, acting under the Delimitation Act, 2002, redrew Parliamentary and Assembly constituency boundaries using the 2001 census, and also re-fixed SC/ST reserved seats under Articles 330 and 332 on the same basis. The exercise it replaced had been based on the 1971 census — meaning constituency boundaries stood unchanged for three decades even as population distribution shifted sharply, including large-scale rural-to-urban migration.

The 84th and 87th Amendments: Freezing the Seat Count

A long-standing concern with delimitation is that it can penalise States that succeeded in controlling population growth, since faster-growing States would gain more seats. To address this, the 84th Constitutional Amendment Act, 2001 and the 87th Constitutional Amendment Act, 2003 amended Articles 82 and 170 (among others). Their combined effect is twofold:

• The total number of Lok Sabha seats allocated to each State, as fixed on the basis of the 1971 census, remains unaltered until the first census taken after the year 2026.
• The total number of seats in the Legislative Assembly of every State, similarly fixed on the 1971 census basis, also remains unaltered until the same date.

In effect, the 2001-census-based Fourth Delimitation Commission could redraw constituency boundaries within each State and re-fix SC/ST reservation, but it could not alter how many Lok Sabha or Assembly seats each State gets relative to others — that allocation still rests on the 1971 census and stays frozen until a post-2026 census is taken.

Delimitation and the Representation of the People Act, 1950

The Representation of the People Act, 1950 does not itself conduct elections; it lays the groundwork by providing for the allocation of seats to and the delimitation of constituencies for the Lok Sabha and State Legislatures, the qualifications of voters, and the preparation of electoral rolls. Actual conduct of elections is governed separately by the Representation of the People Act, 1951. Delimitation therefore operates as a preparatory constitutional-cum-statutory exercise that determines the electoral map on which subsequent elections under the 1951 Act are held.

Why Delimitation Matters

Delimitation keeps the principle of "one vote, one value" workable by preventing constituencies from becoming too unequal in population over time. It also determines how many seats a State sends to the Lok Sabha and how SC/ST reservation is distributed within it — decisions with direct political and federal significance, which is why the seat-count freeze until 2026 remains a live issue in debates on federalism and representation.

UPSC Relevance

Prelims

• Articles 81, 82, 170, 330 and 332 deal with delimitation and reserved-seat re-fixing.
• Four Delimitation Commissions have been constituted so far — 1952, 1963, 1973 and 2002.
• The current seat allocation is based on the 1971 census and is frozen till the first census after 2026.

Mains

• Examine how the 84th and 87th Amendments sought to balance population-based representation with fairness to States that controlled population growth.
• Discuss the federal and political implications of ending the freeze on Lok Sabha seat allocation after the next delimitation exercise.

FAQ

Q1. What is delimitation of constituencies? It is the process of redrawing the boundaries of Lok Sabha and Assembly constituencies, and re-fixing SC/ST reserved seats, after each census, as provided under Article 82 read with Articles 170, 330 and 332.

Q2. Which census is the current Lok Sabha seat allocation based on? The current allocation of Lok Sabha seats among States is based on the 1971 census, and is frozen until the first census taken after 2026, by virtue of the 84th and 87th Constitutional Amendments.

Q3. Who carries out delimitation? An independent Delimitation Commission, constituted by Parliament through a specific Act, carries out the exercise; it is not done directly by the Government.

Q4. How many Delimitation Commissions has India had? Four — in 1952, 1963, 1973 and 2002, under the Delimitation Commission Act 1952, Delimitation Commission Act 1962, Delimitation Act 1972 and Delimitation Act 2002 respectively.

Q5. Does delimitation change the total number of seats a State has? Under the current freeze, delimitation can redraw constituency boundaries within a State but cannot change the total Lok Sabha or Assembly seats allotted to that State until the freeze lifts after the first census following 2026.

Quick Revision

• Article 82: readjustment of Lok Sabha seats/constituencies after each census.
• Article 170: same principle for State Assemblies.
• Articles 330, 332: re-fixing of SC/ST reserved seats.
• Four Delimitation Commissions: 1952, 1963, 1973, 2002.
• Fourth Commission (2002 Act) used the 2001 census for constituency boundaries.
• Seat allocation among States still based on 1971 census, frozen till first census after 2026 (84th and 87th Amendments).

Sources

• The Constitution of India, Article 82 — https://legislative.gov.in/constitution-of-india
• The Constitution of India, Articles 170, 330, 332 — https://legislative.gov.in/constitution-of-india
• Delimitation Act, 2002 — https://legislative.gov.in

Further Reference

For deeper reading on this topic and the wider polity syllabus, these standard works are recommended:

• M. Laxmikanth, Indian Polity (McGraw Hill) — the standard UPSC handbook.
• D.D. Basu, Introduction to the Constitution of India (LexisNexis) — authoritative constitutional-law treatment.
• The Constitution of India — Bare Act — the official text.

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