- Mark ElliottMark ElliottProfessor of Public Law, University of Cambridge
- and Jason VaruhasJason VaruhasAssociate Professor, University of Melbourne
This chapter examines the status of unlawful administrative action, and more specifically whether unlawful administrative action is void or voidable. It first considers the practical and theoretical arguments that address the ‘void or voidable’ question by focusing on the case of Boddington v. British Transport Police  2 AC 143, along with four post-Boddington decisions. It then discusses the nature of voidness, with particular emphasis on the presumption of validity and the principle of legal relativity. It also explores the divergent theoretical perspectives upon administrative law that underpin the different approaches that writers adopt to the status of unlawful administrative acts. Finally, it looks at voidness in relation to collateral challenge and suggests that the disagreements regarding the status of unlawful administrative action, at least to some extent, pertain not to what constitutes a desirable outcome but to the form of judicial reasoning that prefigures the reaching of the outcome.