Thanks for your question – it’s a great one!
It’s true - the Prime Minister and the Cabinet are not mentioned in the Australian Constitution. In fact, the Constitution does not cover all aspects of how Australia is governed. Many aspects of our system of government operate by tradition, similar to Britain.
The Prime Minister and Cabinet are mentioned in legislative acts (or laws). Sometimes their powers and responsibilities are described, but only as it relates to specific duties, rather than defining the overall role. Political parties are not defined by Acts of Parliament.