It is necessary to identify the basic features of the Constitution which are non-amendable under Art. 368. The question has been considered by the Court from time to time, and several such features have been identified, but the matter still remains an open one; no exhaustive list of such features has yet emerged and the Court has to decide from case to case whether a constitutional feature can be characterised as basic or not.
In the seminal Kesavananda case, Sikri Chief Justice mentioned the following as the "basic foundation and structure" of the Constitution:
- Supremacy of the Constitution;
- Separation of Powers between the legislature, the executive and the judiciary;
- Republican and democratic form of Government;
- Secular character of the Constitution,
- Federal Character of the Constitution,
- The dignity of the individual secured by the various Fundamental Rights and the mandate to build a welfare state contained in the directive principles;
- The unity and integrity of the nation
- Parliamentary system.
The above features have been mentioned as only illustrative and the list is not by any means exhaustive. Whether a feature of the Constitution is 'basic' or not is to be determined from time to time by the court as and when question arises.
Since Kesavananda, the matter has been considered by the Supreme Court is several cases and the Court has had occasion to declare several features of the Constitution as fundamental features or part of basic structure of the constitution of India.
In Kihoto Hollohon, the Supreme Court has declared Democracy is the basic feature of the constitution.
In the same judgment Verma J. in his minority judgment declared : Democracy is a part of the basic structure of our Constitution; and the rule of law, and free and fair elections are basic features of democracy.
In Bommai Case, it has been observed: Democracy and Federalism are essential features of our Constitution and are part of its basic structure.
In the same judgment Supreme Court has ruled that secularism is a basic or an essential feature of the Constitution.
In Indira Gandhi vs Rajnarain, the Supreme Court has unequivocally ruled that the Preamble to the Indian Constitution guarantees equality of status and of opportunity and that the Rule of law is the basic structure of the Constitution.
In plethora of cases, the Supreme Court has asserted that independence of Judiciary is a basic feature of the Constitution as it is the sine qua non of the democracy; it is the most essential characteristic of a free society.