Wilson & Kable: The Doctrine of Incompatibflity - An Alternative to Separation of Powers?

Abstract

The recent decisions of the High Court in Wilson v Minister for Aboriginal and Torres Strait Islander Affairs and Kable v Director of Public Prosecutions (NSW) are the latest developments in the preservation of judicial independence in Australia. Both decisions apply in quite different circumstances a doctrine of incompatibility which is designed to protect the independence and impartiality of the judicial branch. Wilson established a restriction on Commonwealth power in relation to the appointment of federal judges persona designata while Kable established a restriction on State power in relation to the vesting of non-judicial power in State Supreme Courts. This article considers whether the same doctrine of incompatibility was applied in the quite different circumstances of each case, the nature of incompatibility and the ramifications of these decisions for the Commonwealth and especially for the States. In particular it is suggested that the reliance on Ch III in Kable provides a basis for further restrictions on State Parliaments comparable to those which apply to the Commonwealth Parliament by virtue of the doctrine of the separation of judicial power. These further restrictions on the States like that in Kable are the consequence not of a separation of powers as such but of the need to maintain the independence of the courts vested with federal judicial power. The decision in Kable is a further instance of a restriction on Commonwealth power being extended to the States by virtue of the indivisibility of Commonwealth and State affairs.