The Parliament of Canada is the legislative body of the Government of Canada. The Parliament is composed of the House of Commons (lower house), the Senate (upper house), and the Sovereign, represented by the Governor General. Most major legislation originates from the House, as it is the only body that is directly elected. A new parliament begins after an election of the House of Commons and can sit for up to five years. The number of seats in parliament has varied as new provinces joined the country and as population distribution between the provinces changed; there are currently 338 House MPs and 105 Senators (when there are no vacancies).