Keshavananda Bharati case (1973) was the landmark in constitutional history as Supreme Court formulated the basic structure doctrine.

Keshavananda Bharati case (1973) was the landmark in constitutional history as Supreme Court formulated the basic structure doctrine. It states that parliament (constituent power of parliament) can't amend basic features fundamental of constitution. Limitless judicial authority due to checkup and ambiguity of basic structure doctrine - Judiciary has power to define what are the basic structure of constitution - Various judgements like Indira Gandhi v. Raj Narain (1975), Minerva Mills case (1980) Indira Sawhney case → Supreme court used power to strike down parliamentary legislating. - There is no clear definition thus more flexibility with judiciary

— Nidhi Goyal · AIR 91