Amid the recurring debate over whether northern states could gain at the expense of the South in any future Lok Sabha expansion, the historical record tells a more complicated story. Between 1951 and 1977, when parliamentary seats were periodically reallocated after Census exercises, both the Hindi belt and the southern states saw their share of Lok Sabha seats decline. But the Hindi belt’s share fell by far more — 3.1 percentage points, against a 1.2-point decline for the South.The main reason was not a gain for the South over the North, or vice versa, but the growing representation of Union Territories and the rising share of western and eastern states. The comparison also needs to be read with caution: India’s map looked very different in 1951, before the linguistic reorganisation of states. By 1956, states were more or less in their present form, but several UTs either had little or no Lok Sabha representation at the time.

Taken together, the data shows that changes in parliamentary representation were shaped not just by the North-South balance, but also by state reorganisation, UT representation, and the evolving federal map of India.
► The 1951 election was held before the linguistic reorganisation of states, so state boundaries were very different from today’s ► After the 1956 reorganisation, states were broadly in their present form, but several Union Territories still had little or no Lok Sabha representation ► The fall in share was driven partly by the growing representation of UTs and by gains by western and eastern states ► Even in 1977, the last election in this analysis since Lok Sabha seats have not been reallocated after that, Daman & Diu did not exist as a separate UT ► This comparison tracks share of total Lok Sabha seats, not voter population per Member of Parliament or constituency size ►For 1951 and 1957, the figures refer to seats, not constituencies, because some constituencies then elected two members
