Deputy Prime Minister of Australia accepted the view put to him by McEwen that to commission a Liberal temporarily as Prime Minister would give that person an unfair advantage in the forthcoming party room ballot for the permanent leader. McEwen's appointment was in keeping with the previous occasion when the main non-Labor party was without a leader; Earle Page of the Country Party was interim Prime Minister between 7 and 26 April 1939—the period between Joseph Lyons' sudden death and the United Australia Party naming Robert Menzies his successor. Since 1968 only two Deputy Prime Ministers have gone on to become Prime Minister: Paul Keating
Prime Minister of Portugal was sworn in on 24 September 1834, as "Presidente do Conselho de Ministros" (President of the Council of Ministers). In 1911, the official title of the prime minister became "Presidente do Ministério" (President of the Ministry). In 1933, it became again "Presidente do Conselho de Ministros". The present title "Primeiro-Ministro" (Prime Minister), attributed to the head of the Government of Portugal, was officially established by the Constitution of 1976 after the revolution of 25 April 1974 The incumbent Prime Minister of Portugal is António Costa, who took office on 26 November 2015 as the 13th Prime Minister of the Third