The Prime Minister of India is a constitutional institution and the head of the executive government, established under the Constitution of India, 1950. The office is a core feature of India's adoption of the Westminster parliamentary system, which solved the problem of executive accountability by making the government responsible to the elected legislature. The first Prime Minister, Jawaharlal Nehru, took office on 15 August 1947.
The mechanism is primarily governed by Article 74 and Article 75 of the Constitution. Article 74(1) mandates a Council of Ministers with the Prime Minister at its head to aid and advise the President, who must act in accordance with such advice. The President formally appoints the Prime Minister, who is typically the leader of the party or coalition commanding a majority in the Lok Sabha (House of the People). Article 75(3) establishes the principle of collective responsibility, stating that the Council of Ministers is collectively responsible to the Lok Sabha. The Prime Minister is the chief advisor to the President and the main channel of communication between the Council of Ministers and the President.
The office connects directly to the President of India (the constitutional head of state) and the Council of Ministers (the executive body). A significant change was introduced by the 91st Amendment Act of 2003, which amended Article 75 to cap the total number of ministers, including the Prime Minister, at 15% of the total strength of the Lok Sabha. This provision limited the size of the executive, but the fundamental roles and powers of the Prime Minister as the head of government remain unchanged.