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 Vietnam Council of Ministers, the highest executive body of state, from 1981 until it was renamed to Government in the 1992 constitution. The office of prime minister was renamed in the 1980 constitution to that of Chairman of the Council of Ministers. Pham Van Dong, the second Prime Minister of Vietnam, served as North Vietnamese Prime Minister from 1955 until 1976, when he became prime minister of a unified Vietnam, and then until 1987, when he resigned. At his resignation, he was the longest-serving prime minister in Vietnamese history, and the oldest serving prime minister in the world. He often lamented