InDepth | From 543 to 816: The Fertility Factor in India's Delimitation Debate

For decades, India asked states to slow population growth. Many did. Now, as Parliament prepares for a fresh delimitation exercise, several southern states fear that their success in population control could mean they will get a smaller share of political representation in Lok Sabha. 

Since the 1970s, Parliament froze the distribution of Lok Sabha seats among states on the basis of the 1971 Census to encourage population stabilisation, keeping the House at 543 elected seats. 

However, population growth has remained uneven across states. Southern political parties argue that they are being “punished” for successfully controlling population growth. 

The Delimitation Bill, 2026 proposes expanding the Lok Sabha from 543 to 816 elected seats, paving the way for the first nationwide delimitation exercise in decades. 

What is Delimitation?

Delimitation means the act or process of fixing limits or boundaries of territorial constituencies in a country or a province having a legislative body. 

In India, the Delimitation Commission controls all the decisions and its orders have the force of law and cannot be called in question before any court. Four such commissions have been formed in India since independence: in 1952, 1963, 1973, and 2002.  

The Rule

The Constitution states that after every Census, the allocation of Lok Sabha seats among states and the boundaries of parliamentary and Assembly constituencies are to be readjusted. 

The First Census of Independent India was conducted in 1951. And since then, it has been conducted every 10 years. 

The delimitation in the 1950s was based on the 1951 Census. The Lok Sabha seats in the first general election in 1951-52 stood at 489. After the delimitation, the 1957 election had 494 Lok Sabha seats. 

The seats were again increased in the 1960s with the 1961 Census as the base. By 1967, India’s Lok Sabha seats increased to 520. 

The 1971 Census was followed by another delimitation exercise, increasing the elected strength to 542. It became 543 in 1977 after Sikkim was allotted one Lok Sabha seat. 

However, with the 42nd Amendment Act of 1976, the process of delimitation was formally suspended till the 2000s and the allocation of Lok Sabha seats among states was frozen on the basis of the 1971 Census. In 2001, with the 84th Constitutional Amendment, the date of next delimitation was pushed to the first census after 2026.

Why Does Population Matter?

Article 81 of the Constitution provides that Lok Sabha seats should be allocated to states broadly in proportion to their population. It also requires each state to be divided into parliamentary constituencies so that, as far as practicable, every constituency has roughly the same population.

In simple terms, population is the basis for deciding how many Lok Sabha seats each state gets. States with larger populations are allocated more seats, while those with smaller populations get fewer. Fertility influences population growth over time, and states that reduced fertility earlier generally recorded slower population growth. 

The Fertility Factor 

India reached replacement-level fertility in 2019–21, with the Total Fertility Rate (TFR) falling to 2.0. Replacement-level fertility (about 2.1 children per woman) is the level at which a population replaces itself from one generation to the next, in the absence of migration. 

Kerala was the first Indian state to reach replacement fertility in 1988, when the national TFR was still 4. Tamil Nadu became the second state in 1993 followed by Andhra Pradesh (2001) and Karnataka (2005).

Lower fertility slows population growth over time. Because of the low fertility rate, the southern states experienced slower population growth than the national average. 

Uttar Pradesh and Bihar are yet to achieve this feat. Uttar Pradesh has the highest number of seats at 80. 

Projected Delimitation Based on the 2011 Census  

An analysis by Outlook, using PRS Legislative Research data, shows that if seats are allocated using the 2011 Census under the existing population-based constitutional principle, Uttar Pradesh will get 53 additional seats as compared to just two for Kerala. 

The PRS estimated what will be the state-wise Lok Sabha seats if the House expands by 50% and seats are allocated based on population using the 2011 Census. 

Under the PRS projection, Uttar Pradesh will gain 53 seats while Bihar will gain 29 seats. Madhya Pradesh will be the third biggest gainer at 19. In total, only nine states are projected to gain seats in double digits, including Maharashtra (27), West Bengal (19) and Gujarat (14). These three states reached replacement-level fertility only in 2015. 

Five northern states – UP, Bihar, Rajasthan, Madhya Pradesh and Haryana – will alone get 129 additional seats, the PRS projection suggests. 

The PRS also suggests that if seats are allocated using the 2011 Census under the existing constitutional principle, the southern states' share of Lok Sabha seats would decline relative to the north. This, in turn, would diminish the South’s political influence in Parliament despite an increase in the overall strength of the House.

The Delimitation Bill, 2026 

The Delimitation Bill, 2026 proposes increasing the elected strength of the Lok Sabha to 816 seats—273 more than the current 543.

Union Home Minister Amit Shah in April said that the proposed Delimitation Bill, 2026 will not harm the southern states but will, in fact, benefit them. Introducing the 50% increase model, he explained, the total seats from five southern states will increase by 66 from the existing 129 to 195. Under the 50% increase model, their share in the total seats of the House will remain almost the same at around 24 per cent. 

So, if the delimitation were carried out based on the 2011 Census, the PRS calculation shows that Kerala will see an increase of only two Lok Sabha seats while Tamil Nadu will see an increase of nine seats. However, the calculation shared by Shah in Lok Sabha shows that Kerala will get 10 more seats in the Parliament, raising its total representation to 30, while Tamil Nadu will see a rise of 20 seats in its tally to 59, under the 50% increase model.

Shah listed the changes in all the five southern states. He also said that Andhra Pradesh currently has 25 seats, with a representation of about 4.60 per cent in the 543-member House. 

“After the proposed changes, with an increase of around 50 percent, the number of seats will rise to 38, and Andhra Pradesh’s representation will increase to about 4.65 per cent.  Similarly, Telangana currently has 17 seats, with a representation of about 3.13 percent in the existing Lok Sabha. After the proposed increase, the number of seats will go up to 26, and its representation will reach around 3.18 percent,” he added. 

However, he has not yet disclosed the proposed seat allocation for other states. Until those figures are made public, any assessment of the final distribution of seats across states remains incomplete.

The Political Stand

The Dravida Munnetra Kazhagam (DMK) states that the Union Government’s move to resume the delimitation process aligns with constitutional provisions, but it has raised widespread concern and opposition. 

“Many critics view this as a calculated attempt to strengthen the BJP's political base, particularly in the Hindi-speaking Northern states, where population growth remains high. This would potentially expand the BJP's representation in Parliament,” the DMK stated.

In contrast, states like Tamil Nadu, Kerala, and other Southern states, which have made remarkable progress in controlling population growth, “may stand to lose seats, thereby reducing their influence at the national level”, it said.

Congress said that by the 1970s, “a dangerous federal fault line” had emerged. 

“The southern states… had responded responsibly to the national call for family planning. They invested in women’s education, healthcare, and social reform, bringing their fertility rates down dramatically,” the party added. The northern states, by contrast, lagged far behind on every one of these indicators, the Congress said.

Just as the government, the BJP has also maintained the stand that “there will be no injustice to southern states” in delimitation. 

“Their representation will increase from 23.76% (129 out of 543 seats) to 23.90% (195 out of 816 seats). This is a proportionate rise, not a reduction. The same principle applies to every state,” the BJP said. 

Road Ahead

The Monsoon Session of Parliament is scheduled from July 20 to August 13, with delimitation expected to remain part of the broader political discussion. 

With the Census underway and the proposed delimitation exercise on the horizon, India is preparing for its first nationwide redrawing of Lok Sabha constituencies in more than five decades. 

While the Constitution links representation to population, the government has indicated that the revised formula will also protect the southern states' share of Lok Sabha seats. However, until a final formula for redistributing Lok Sabha seats is made public, the debate over delimitation is likely to continue, with population, representation and federal balance remaining at the centre of the discussion.