The Non-Identical Twins in UK Public Law: Reasonableness and Proportionality

Abstract

Ever since the Wednesbury decision in 1947 (Associated Provincial Picture Houses Ltd v Wednesbury Corporation [1948] 1 KB 223) courts and public law scholars in the United Kingdom (UK) have been struggling to comprehend the meaning of ‘reasonableness’ and its relation to ‘proportionality’. The main purpose of this article is to promote conceptual clarity in UK public law by describing the nature of reasonableness and proportionality as grounds of judicial review and by highlighting the overlooked similarities and differences between them.The main arguments of this article are that: (i) reasonableness is, in essence, an exercise in balancing and weighing; (ii) proportionality adds very little to the existing grounds of judicial review in UK public law; (iii) this addition is not necessarily focused on the administrative weighing and balancing process; and (iv) since proportionality adds very little to the existing grounds of judicial review, there is no conceptual or normative reason to prevent having proportionality as a general ground of judicial review in UK public law.