The original thesis of this book is that, in Australia, natural justice has become an aspect of constitutional rather than administrative law. This view of procedural justice is developed in the context of UK and Commonwealth law in a way that brings both historical and doctrinal research to bear on important contemporary issues in judicial review. The author traces the origins and fluctuating development of the idea and practice of natural justice in England and its adaptation to the planned state in Australia. Consideration is given to the impact of the so-called new property and the broadening protection of citizens' rights, the growing significance of the doctrine of legitimate expectations, and the changing role of the notion of ultra vires as a legitimizing basis for judicial review. The book culminates in a critical examination of the idea of common law constitutionalism and the need to develop present-day rationales for the protection of procedural rights.