1949 Australian federal election of Representatives was enlarged from 74 to 121 seats and the Senate from 36 members to 60 members. All 121 lower house seats, and 42 of the 60 upper house seats, were up for election. The Chifley Government was defeated, ending the longest period of Labor Federal Government in Australian history up to that date (1941–49). Labor would not return to office until 1972. Robert Menzies became Prime Minister for the second time, and the Liberal Party of Australia won government federally for the first time. 1949 Australian federal election Federal elections were held in Australia on 10 December 1949.
Prime Minister of Australia becomes acting Prime Minister in those circumstances. Three Prime Ministers have died in office – Joseph Lyons (1939), John Curtin (1945) and Harold Holt (1967). In each of these cases, the Deputy Prime Minister (an unofficial office at the time) became an interim Prime Minister, pending an election of a new leader of the government party. In none of these cases was the interim Prime Minister successful at the subsequent election. As of , there are seven living former Australian Prime Ministers. The greatest number of living former Prime Ministers at any one time was eight. This has occurred twice: