According to Article 75(5) of the Constitution, a minister who for any period of six consecutive months is not a member of either House of Parliament shall at the expiration of that period cease to be a minister. Since the Prime Minister is the head of the Council of Ministers, this provision applies to the office. Furthermore, the Supreme Court ruled in 1997 that a person who is not a member of either House of Parliament can be appointed as Prime Minister for six months, within which he/she must become a member of either the Lok Sabha or the Rajya Sabha; otherwise, he/she ceases to be the Prime Minister.