NEW DELHI — A constitutional amendment that would have expanded the Lok Sabha to as many as 850 seats and redrawn representation on the basis of the 2011 census was defeated in Parliament in April, sparing for now the states that had most successfully controlled their populations the reward of a smaller share of seats.

Seat allocation has been frozen on the 1971 census for roughly five decades, an arrangement introduced expressly as a "motivational measure" to encourage states to stabilise their populations. Several of the states that complied now report fertility rates well below replacement, and stood to lose parliamentary weight the moment the freeze was lifted, while states that missed the targets would have gained influence in rough proportion to the amount by which they missed them.

The amendment fell 54 votes short of the required two-thirds, after which the government withdrew the accompanying delimitation bill. An official described the outcome as a procedural delay, noting that the underlying arithmetic, in which the states that followed national policy most faithfully end up counting for less, remained intact and available for reintroduction.

The disciplined states were assured the principle had not been abandoned, only deferred, and that their decades of cooperation would be acknowledged in due course and in the appropriate proportion. A spokesperson confirmed the relevant census would be held eventually, and that states were free to keep controlling their populations in the meantime, should they wish to be thanked again.