Under the 1976 Constitution, the President is the nominal source of executive power. Like the British Sovereign (and heads of state in other Westminster Systems), he or she "reigns but does not rule". In practice, executive authority is exercised by the Prime Minister and his or her Cabinet, on behalf of the President. The President appoints as Prime Minister the leader of the largest party in the House of Representatives, and also appoints members of the Senate on the recommendation of the Prime Minister and the Leader of the Opposition. The President must be at least 35 years old (although no President has been younger than 59), a citizen of Trinidad and Tobago, and at the time of nomination must have been resident in the country for an unbroken period of ten years.