The Constitution of India
Article 170
Composition of the Legislative Assemblies
(1) Subject to the provisions of article 333, the Legislative Assembly of each State shall consist of not more than five hundred, and not less than sixty, members chosen by direct election from territorial constituencies in the State.
(2) For the purposes of clause (1), each State shall be divided into territorial constituencies in such manner that the ratio between the population of each constituency and the number of seats allotted to it shall, so far as practicable, be the same throughout the State.
Explanation.—In this clause, the expression “population” means the population as ascertained at the last preceding census of which the relevant figures have been published:
Provided that the reference in this Explanation to the last preceding census of which the relevant figures have been published published shall, until the relevant figures for the first census taken after the year 2026 have been published, be construed as a reference to the 2001 census.
(3) Upon the completion of each census, the total number of seats in the Legislative Assembly of each State 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:
Provided that such readjustment shall not affect representation in the Legislative Assembly until the dissolution of the then existing Assembly:
Provided further that such readjustment shall take effect from such date as the President may, by order, specify and until such readjustment takes effect, any election to the Legislative Assembly may be held on the basis of the territorial constituencies existing before such readjustment:
Provided also that until the relevant figures for the first census taken after the year 2026 have been published, it shall not be necessary to readjust— (i) the total number of seats in the Legislative Assembly of each State as readjusted on the basis of the 1971 census; and (ii) the division of such State into territorial constituencies as may be readjusted on the basis of the 2001 census, under this clause.
Why this exists
The framers wanted State assemblies to reflect population fairly, using periodic census data to keep constituencies roughly equal in size. But from the 1970s, there was concern that states pursuing family planning successfully would lose political weight if seats were reallocated strictly on population growth, while high-population states would gain more seats and rewarded for lax population control. This led to a freeze: seat numbers were locked to the 1971 census (via the 42nd and later 84th/87th Amendments), while boundaries could still be updated internally using more recent census data (2001), preserving fairness within existing seat allocations without punishing family-planning-successful states. The freeze has since been extended to after the first census following 2026.
How courts read it
There is no major Supreme Court ruling striking down or reinterpreting Article 170 itself; most litigation on delimitation focuses on the Delimitation Commission's actions and related laws (like the Delimitation Act) rather than this Article directly. Courts have generally deferred to Parliament's authority to determine the 'manner' of readjustment under clause (3), treating this as largely a political and administrative matter for Parliament and the Election Commission/Delimitation Commission to execute, not something for the judiciary to second-guess in detail.
Common misconceptions
- Myth: State assembly seats automatically increase whenever a state's population grows.
Fact: Since 1976, total seats have been frozen based on the 1971 census, and this freeze is extended until after the first census taken after 2026. - Myth: Constituency boundaries never change under this freeze.
Fact: While total seat numbers are frozen, boundaries of constituencies can still be redrawn (using 2001 census data) to balance population within the existing seats. - Myth: Article 170 lets Parliament change the maximum/minimum seat limits (60–500) whenever it wants.
Fact: The 60–500 range is fixed in the Constitution itself; Parliament's role under clause (3) is only about redistributing seats and boundaries within State legislatures, not altering these constitutional limits.