The next delimitation of India's Lok Sabha constituencies is set to begin following the publication of the 2027 census, triggering a redistribution of parliamentary seats that could reshape national politics for a generation. The constitutional freeze on seat reallocation, in place since 1976, expires after the census conducted on March 1, 2027, enabling the formation of a Delimitation Commission whose binding orders will determine the new electoral map. This process will allocate seats by population, disadvantaging southern states with lower fertility rates and rewarding high-growth northern regions.

Projections based on 2011 census data and analyses by PRS Legislative Research and The Hindu indicate Tamil Nadu could lose seven seats, falling from 39 to 32, while Kerala would drop from 20 to 15. Uttar Pradesh is expected to gain at least nine seats, rising to 89, with Bihar and Rajasthan gaining six and five respectively. In a larger House of 815 seats, as proposed in the failed 131st Amendment Bill, Uttar Pradesh could gain up to 58 seats, significantly increasing the political weight of the Hindi heartland.

The Modi government's attempt to advance delimitation through the Constitution (131st Amendment) Bill, 2026, failed in the Lok Sabha on April 17, 2026, after securing only 298 votes—54 short of the required two-thirds majority. Despite the bill's withdrawal, the delimitation process remains constitutionally inevitable after the 2027 census. A commission, typically headed by a retired Supreme Court judge, will be constituted to redraw boundaries, and its decisions will be final and legally binding, immune from judicial challenge.

Southern states, particularly Tamil Nadu and Kerala, have raised concerns over what analysts call a 'demographic penalty,' where successful family planning has led to below-replacement fertility rates—1.7 and 1.8 respectively—now translating into reduced political representation. Critics argue the current system disincentivizes population control, while northern states with higher growth rates stand to gain long-term dominance in Parliament.

The Delimitation Commission is expected to be constituted in 2028, with final orders likely by 2030. The new seat allocation will remain in effect for approximately 25 years, setting the stage for a lasting shift in India's political power structure.