The Future of Wednesbury Unreasonableness in the Substantive Review of Administrative Discretion: A Hong Kong Perspective

The continued use of Wednesbury unreasonableness in the substantive review of administrative discretion has received considerable scholarly attention throughout the common law world. Recent local developments in proportionality review bring this debate to the fore in Hong Kong. It has been argued that the Court of Final Appeal’s articulation of a sliding scale of proportionality review has strengthened the case for the formal abolition of Wednesbury unreasonableness, on the basis that proportionality has now embraced an identical unreasonableness standard. This article challenges the claim that Wednesbury is now a redundant concept in Hong Kong public law. Descriptively, there remain material differences between Wednesbury and proportionality, even under its modified deferential form. Normatively, too, Wednesbury remains justified as a means to recognize the limited general basis in which common law substantive review can occur. A conflation of Wednesbury unreasonableness and proportionality can have the unintended consequence of diluting constitutional protections. Furthermore, the emergence of a sliding scale of Wednesbury review in Hong Kong reduces, rather than increases, pressure for its abolition in favour of proportionality.