Most defections originated from three major parties -- the Congress, BJP and BSP. IMAGE: Bharatiya Janata Party President Nitin Nabin offers sweets to Aam Aadmi Party's Rajya Sabha MP Raghav Chadha at the party headquarters in New Delhi, April 24, 2026, after he, along with two other AAP Rajya Sabha MPs Sandeep Pathak and Ashok Mittal, joined the BJP. More than 1,100 MPs and MLAs switched political parties across three Lok Sabha terms between 2009 and 2024.