 The War Cabinet comprised senior MP's from the Government and Opposition parties.The Defence Secretariat occupied the second floor of 'A Block New Wing' which also contained the office of senior military staff, the Secretary of the Department Defence (Sir Frederick Shedden), visiting Ministers of State and their secretaries and support staff, and the War Cabinet room.The wartime Prime Ministers (Robert Menzies and later John Curtin) also had offices near the War Cabinet Room throughout the War.