The Doctrine of Basic Structure is a fundamental principle in Indian constitutional law that holds that certain core features of the Constitution cannot be altered or destroyed by any amendment made by Parliament. This doctrine serves as a limitation on Parliament’s power under Article 368, which grants the power to amend the Constitution.

The doctrine was first laid down by the Supreme Court in the landmark case of Kesavananda Bharati v. State of Kerala (1973). In this case, a 13-judge bench—the largest in Indian judicial history—ruled that while Parliament has wide powers to amend the Constitution, it cannot alter the "basic structure" or essential features of the Constitution. These basic features were not exhaustively listed, but the court identified some key components such as:

Supremacy of the Constitution,

Rule of law,

Separation of powers,

Federalism,

Judicial review,

Free and fair elections,

Secularism,

Democracy, and

The dignity of the individual.

Since Kesavananda Bharati, the Supreme Court has applied the Basic Structure Doctrine in several cases to strike down constitutional amendments that it found to be in violation of the essential features of the Constitution. For example, in Indira Nehru Gandhi v. Raj Narain (1975), the court struck down a constitutional amendment that sought to exempt the election of the Prime Minister from judicial review, stating that it violated the principle of free and fair elections and judicial review—both part of the basic structure.

Similarly, in Minerva Mills v. Union of India (1980), the Supreme Court invalidated parts of the 42nd Amendment for attempting to give unlimited amending power to Parliament and curtailing judicial review. The court reaffirmed that a balance between Fundamental Rights and Directive Principles of State Policy is part of the Constitution’s basic structure.

In I.R. Coelho v. State of Tamil Nadu (2007), the court held that even laws placed under the Ninth Schedule of the Constitution (which protects them from judicial review) can be tested against the basic structure if they violate fundamental rights.

In essence, the Basic Structure Doctrine ensures that India’s constitutional identity is preserved, even in the face of political or legislative majorities. It acts as a constitutional check on Parliament’s power and upholds the idea that the Constitution is a living document with enduring principles that cannot be overwritten by transient political interests.