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
Secretary of the Department of the Prime Minister and Cabinet (Australia) the list of Secretaries, since the first appointment was made on 1 January 1912. Within days of John Gorton becoming Prime Minister, the functions of the Prime Minister's Department was split and a Department of the Cabinet Office was established. On taking office as Prime Minister in 1971, William McMahon reversed Gorton's changes and restored earlier changes via the creation of the Department of the Prime Minister and Cabinet. A lesser role of Secretary to the Department of the Vice-President of the Executive Council was established for a short time; abolished in the early days of the Whitlam government. Upon