The readjustment of territorial constituencies within states on the basis of the 2001 Census, without changing the number of seats allotted to each state, was provided for by the:

The 87th Constitutional Amendment Act, 2003, provided that the territorial constituencies within each state would be readjusted (delimited) on the basis of the 2001 Census.

Background:

• The number of seats allotted to each state in the Lok Sabha and the state assemblies is based on population.
• To encourage family planning, the 42nd Amendment (1976) froze the allocation of seats among the states on the basis of the 1971 Census until the year 2000.
• The 84th Amendment (2001) extended this freeze on the number of seats allotted to the states until the first census after 2026.
• However, the 84th Amendment allowed the readjustment of the boundaries of constituencies within each state on the basis of the 1991 Census.

The 87th Amendment:

• It changed the basis of this readjustment of constituencies from the 1991 Census to the 2001 Census.
• The total number of seats in each state remained the same; only the boundaries of the constituencies and the number of seats reserved for the Scheduled Castes and Scheduled Tribes were changed.

The Delimitation Commission (2002):

• The Delimitation Commission headed by Justice Kuldip Singh redrew the boundaries of the parliamentary and assembly constituencies on the basis of the 2001 Census.
• The new constituencies were used for the first time in the elections held from 2008 onwards, including the Lok Sabha elections of 2009.

Why delimitation is needed:

• Populations change over time, and some constituencies become much larger than others.
• Delimitation ensures that each constituency has roughly the same number of voters, so that every vote has roughly equal value.

Future delimitation:

• The freeze on the number of seats of each state will end after the first census taken after 2026, when the seats may be reallocated among the states on the basis of population.
• This is a matter of debate, because states that have controlled their population growth fear that they may lose seats.

Why not the other options?

• ✗The 42nd Amendment froze seats on the basis of the 1971 Census; the 84th Amendment extended the freeze and used the 1991 Census; the 95th Amendment dealt with other matters.