does canada's prime minister hold a seat in the house of commons
Though it does not formally elect the prime minister, the House of Commons indirectly controls the premiership. By convention, the prime minister is answerable to, and must maintain the support of, the House of Commons. Thus, whenever the office of prime minister falls vacant, the governor general has the duty of appointing the person most likely to command the support of the House--normally the leader of the largest party in the lower house, although the system allows a coalition of two or more parties. This has not happened in the Canadian federal parliament, but has occurred in Canadian provinces. The leader of the second-largest party (or in the case of a coalition, the largest party out of government) usually becomes the Leader of the Official Opposition. Moreover, the prime minister is, by unwritten convention, a member of the House of Commons, rather than of the Senate. Only two prime ministers governed from the Senate: Sir John Abbott (1891--1892) and Sir Mackenzie Bowell (1894--1896). Both men got the job following the death of a Prime Minister, and did not contest elections.
House of Commons of Canada