The Constitution of India, the longest and the most exhaustive constitution of any independent nation in the world, came into force on January 26, 1950. The preamble of the constitution defines India as a sovereign, socialist, secular, democratic republic. India has a quasi-federal form of government and a bicameral parliament operating under a Westminster-style parliamentary system. It has three branches of governance: the Legislature, Executive, and Judiciary.
The President of India is the official head of state elected indirectly by an electoral college for a five-year term. The Prime Minister is, however, the de facto head of government and exercises most executive powers. The Prime Minister is appointed by the President and, by convention, is the candidate supported by the party or political alliance holding the majority of seats in the lower house of Parliament.
The legislature of India is the bicameral Parliament, which consists of the upper house called the Rajya Sabha (Council of States) and the lower house called the Lok Sabha (House of People). The Rajya Sabha, a permanent body, has 245 members serving staggered six year terms. Most are elected indirectly by the state and territorial legislatures in proportion to the state’s population. The 543 of the Lok Sabha’s 545 members are directly elected by popular vote to represent individual constituencies for five year terms. The other two members are nominated by the President from the Anglo-Indian community if, in his opinion, the community is not adequately represented.
The executive branch consists of the President, Vice-President, and the Council of Ministers (the Cabinet being its executive committee) headed by the Prime Minister. Any minister holding a portfolio must be a member of either house of parliament. In the Indian parliamentary system, the executive is subordinate to the legislature, with the Prime Minister and his Council being directly responsible to the lower house of the parliament.
India has a unitary three-tier judiciary, consisting of the Supreme Court, headed by the Chief Justice of India, twenty-one High Courts, and a large number of trial courts. The Supreme Court has original jurisdiction over cases involving fundamental rights and over disputes between states and the Centre, and appellate jurisdiction over the High Courts. It is judicially independent, and has the power to declare the law and to strike down union or state laws which contravene the Constitution. The role as the ultimate interpreter of the Constitution is one of the most important functions of the Supreme Court.