The Constitution came into effect on 1 August 1976. Legislative power is vested in the bicameral Parliament, consisting of the Senate, with 31 members, and the House of Representatives, with 41 members. Representatives are elected for a five-year term by universal adult suffrage. The President is a constitutional head of state, chosen by an electoral college of members of the Senate and the House of Representatives. Members of the Senate are nominated by the President in consultation with, and on the advice of, the Prime Minister and the Leader of the Opposition. The Cabinet has effective control of the Government and is responsible to Parliament. Tobago Island was given full internal self-government in 1987. The Tobago House of Assembly has 15 members, of whom 12 are elected; the remaining three members are selected by the majority party. Legislation to increase the number of elected members to 15 was approved in 2021.