The 52nd Amendment (anti-defection law) had specific exceptions: ‘splits’ where 1/3rd of existing party left to form new one; and ‘mergers’ where 2/3rd of existing party joined another.----more----https://theprint.in/politics/raghav-chadha-led-aap-mps-move-to-bjp-reignites-debate-over-merger-exception-to-anti-defection-law/2915914/