Mumbai, Dec. 11 -- The Lok Sabha turned into a lively arena of argument and accusation as members locked horns over electoral reforms and the Special Intensive Revision of voter lists. The discussion, intended to be procedural, quickly evolved into a charged political showdown.

Union Home Minister Amit Shah led the government's defence with a sharp critique of the Opposition. He alleged that rival parties were shielding illegal immigrants to preserve their vote banks and declared that infiltrators cannot be allowed to influence who becomes the country's Prime Minister or Chief Minister. His comments set the tone for a fiery exchange that lasted through the day.

Shah said the ongoing revision of electoral rolls is designed to clean the s...