Harold Wilson imprisoned for fraud, and Sir Eric Miller, who later committed suicide while under police investigation for corruption. The Labour Party held an election to replace Wilson as leader of the Party (and therefore Prime Minister). Six candidates stood in the first ballot; in order of votes they were: Michael Foot, James Callaghan, Roy Jenkins, Tony Benn, Denis Healey and Anthony Crosland. In the third ballot on 5 April, Callaghan defeated Foot in a parliamentary vote of 176 to 137, thus becoming Wilson's successor as Prime Minister and leader of the Labour Party, and he continued to serve as Prime Minister
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: