The central argument of this book is that Australia's constitutional system is essentially that of a federal republic rather than a parliamentary monarchy. Since the Constitution obviously includes both parliamentary and monarchic parts, it is necessary to provide an explanation of federal republic that incorporates these features. It is precisely because the parliamentary and monarchic parts are so obvious that they can be mistaken as the defining features of the Constitution. In addition, there is a strong tradition in Australian political thought that prefers unitary government and the supremacy of parliament. In practical politics this position has been championed by the Australian Labor Party, which for most of the century has been pledged to the abolition of federalism and its replacement by strong centralised government with the States reduced to regional administrative agencies.

Australian parliaments, however, are not sovereign law-makers in the classic Westminster sense. They have limited powers under the Constitution. This is a direct consequence of federalism, which entails two levels of government, Commonwealth and State, of which parliaments are integral parts. In other words, parliaments in the Australian system are the legislative branches of governments that are themselves parts of the larger federal structure with powers allocated by the Constitution. The character of Australian parliaments has been widely misunderstood because of over-ready assumption that they are essentially imitations of the Westminster parliament.