This chapter examines unreasonableness and irrationality as grounds of judicial review. It begins with an examination of Wednesbury unreasonableness as a standard of review, before considering it as both a substantive and a procedural threshold. It is suggested that there may be a lowering of the Wednesbury threshold in Hong Kong, particularly as a standard of procedural review. The intensity of review under Wednesbury unreasonableness is then examined, both as a lower and as a higher intensity of review. It is argued that, and explained how, unreasonableness and irrationality are and should be treated as distinct concepts and grounds of review, before the role of reasons is considered in relation to unreasonableness and irrationality.

This chapter considers the taking into account of irrelevant considerations, and the failure to take into account relevant considerations, as grounds of judicial review. This includes a discussion of the intensity of review if a relevant consideration is taken into account.

This chapter considers two grounds of judicial review which constitute insufficient retention of discretion, namely unlawful delegation, and divestiture and relinquishment. The discussion of unlawful delegation begins by introducing the Carltona principle and a consideration of the extent to which the principle is constitutionally apposite in Hong Kong. Factors such as the status of the delegator and the delegate, the nature of the delegated power and the relationship between agency and delegation, are also considered. The chapter then discusses divestiture and relinquishment of discretion.

This chapter considers breach of legitimate expectations as a ground of judicial review. After introducing the conceptual aspects of this ground, it explores the key requirements for successful establishment of the ground including those relating to the representation (if any) given by the public body, the role of knowledge and (detrimental) reliance, the legitimacy of the applicant’s expectation, legitimate expectation as a relevant consideration when exercising discretion, the role of overriding policy considerations, and both procedural and substantive protection of legitimate expectations by the courts. This includes a discussion of key cases such as Ng Siu Tung v Director of Immigration and R v North and East Devon Health Authority, ex parte Coughlan. Finally, the chapter considers whether and to what extent ultra vires representations can generate legitimate expectations.

This chapter discusses improper purposes, improper motives and abuse of power as grounds of judicial review. The discussion of improper purposes and improper motives includes consideration of multiple purposes or motives and the approach of the courts in determining the legality of a decision-maker’s actions in such a case. Abuse of power and misuse of power form the subject of discussion in the remainder of the chapter.

This chapter gives a detailed discussion of procedural fairness, procedural impropriety and natural justice as grounds of judicial review. It begins with the right to a fair hearing, including the right to an oral hearing and the circumstances in which such a right can be asserted. It then proceeds to examine the right to representation, including legal representation. An overview of the duty of disclosure is given, before the duty to give adequate reasons is examined. Finally, bias and insufficient impartiality are explored, both as encountered in judges and other adjudicators, or in administrative decision-makers.

This chapter discusses error of fact and error of law as grounds of judicial review. It addresses both jurisdictional and non-jurisdictional error of fact, as well as the admission of fresh evidence. It then considers error of law and the uncertain approach taken to Anisminic in Hong Kong. It concludes with a consideration of the distinction between error of fact and error of law.

This chapter gives a detailed discussion of fettering of discretion as a ground of judicial review. It begins by examining the obligation to decide, before addressing the obligation to decide with a sufficiently open mind or without a predetermined outcome. It considers both unlawful policies and the unlawful application of otherwise lawful policies. The chapter concludes with a discussion of fettering through contract.

This chapter discusses a number of important factors relevant to the grounds of judicial review. It begins with a consideration of authority and agency in public law, including the tortious liability of a public body. It then turns to consider ancillary and implied powers which may be asserted by a public body, followed by a discussion of the effect of non-compliance with statutory requirements, including the distinction between so-called mandatory and directory requirements. The chapter then considers estoppel, acquiescence, waiver and consent in the context of judicial review, before addressing res judicata as cause of action estoppel. Finally, the chapter concludes with a discussion of ambiguity and uncertainty as a ground of judicial review.

This chapter provides a brief overview of the grounds of judicial review. It includes a discussion of the classification of the grounds of review and argues that Lord Diplock’s classification in Council of Civil Service Unions v Minister for the Civil Service should not be treated as definitive. Moreover, this classification is not followed in the present book for reasons that are explained.