The Westminister-style bicameral Parliament of Antigua and Barbuda consists of Her Majesty the Queen of England (represented by a Governor-General), an appointed Senate and an elected House of Representatives. The Parliament consists of the 19-member House of Representatives, responsible for introducing legislation, and the 17-member Senate, which reviews and gives assent to proposed legislation.

Representatives are elected by popular vote in general elections that are constitutionally mandated every five years but may be called earlier. Senators are appointed by the Governor General. The major figures in Parliament and the government come from the House of Representatives. The Prime Minister is the leader of the party that holds the majority of seats in the House; the Opposition Leader is the representative, appointed by the Governor General, who appears to have the greatest support of those members opposed to the majority government.

The Prime Minister creates an executive government and advises the Governor General on the appointments to thirteen of the seventeen seats in the Senate. The leader of the opposition, recognized constitutionally, is responsible for advising the Governor General on the appointment of the remaining four senators to represent the opposition in the Senate. The Opposition Leader also consults with the Governor General, in conjunction with the Prime Minister, on the composition of other appointed bodies and commissions. In this way, the opposition is ensured a voice in government.