The High Court’s Prudential Approach to Constitutional Adjudication: When Is It Necessary to Resolve a Constitutional Question?

Despite having a central constitutional function of determining the validity of legislation, the High Court of Australia adopts a variety of principles and doctrines that can result in it declining to resolve constitutional questions. One way this can occur is by only deciding constitutional questions when they are ‘necessary to do justice in the case and to determine the rights of parties’. Although this practice has been followed since the Court’s earliest days, it was only recently labelled the ‘prudential approach’ to resolving constitutional questions by the plurality in Mineralogy Pty Ltd v Western Australia. This article seeks to identify the different ways in which the prudential approach can be followed and why the High Court adopts the practice. It will then turn to analyse the High Court’s adherence to the practice during the tenure of Kiefel CJ, arguing that the Court’s application would benefit from greater clarity and consistency.