The Constitution of India is the supreme legal document of India, and the longest written national constitution in the world. The document lays down the framework that demarcates fundamental political code, structure, procedures, powers, and duties of government institutions and sets out fundamental rights, directive principles, and the duties of citizens.
It espouses constitutional supremacy (not parliamentary supremacy found in the United Kingdom, since it was created by a constituent assembly rather than Parliament) and was adopted with a declaration in its preamble. The Indian Constitution does not contain a provision to limit the powers of the parliament to amend the constitution. However, the Supreme Court in Kesavananda Bharati v. State of Kerala held that there were certain features of the Constitution so integral to its functioning and existence that they could never be cut out of the constitution (known as the 'Basic Structure' Doctrine).