The Basic Structure Doctrine is a judicial concept that acts as a fundamental limitation on the Parliament's power to amend the Constitution of India. It was created to solve the problem of an unlimited amending power, which could potentially be used by a temporary parliamentary majority to destroy the core identity of the Constitution.
The doctrine's origin lies in the landmark Supreme Court judgment of Kesavananda Bharati v. State of Kerala on April 24, 1973. The ratio decidendi of the 7:6 majority decision was that while Parliament may amend any provision of the Constitution under Article 368, it cannot alter or destroy the Constitution's basic structure.
The mechanism works by allowing the Supreme Court to exercise its power of Judicial Review to strike down any constitutional amendment that violates this unwritten core. Although the Court has never provided an exhaustive list, key features consistently recognized as part of the basic structure include the Supremacy of the Constitution, the Rule of Law, Judicial Review, Federalism, Secularism, and the Separation of Powers.
The doctrine connects directly to the 24th Constitutional Amendment Act, 1971, which Parliament passed to assert its absolute amending power, and the subsequent 42nd Amendment Act, 1976, which attempted to place constitutional amendments beyond judicial scrutiny. The doctrine was reaffirmed and evolved in Minerva Mills v. Union of India (1980), where the Court invalidated parts of the 42nd Amendment, ruling that Parliament cannot use its limited amending power to grant itself unlimited power. More recently, the doctrine was used to strike down the 99th Amendment Act, 2014, which established the National Judicial Appointments Commission (NJAC), on the grounds that it violated the basic structure of the Independence of the Judiciary.