Manifest Unreasonableness in the UK Supreme Court: A Doctrine Working Itself Pure

The role and nature of substantive review in UK administrative law doctrine is a perpetual source of debate. Its potential to infringe upon the merits of administrative decision-making, and associated concerns over ensuring a legitimate separation of powers, make this inevitable. Debates have concerned whether Wednesbury review should exist at all, whether there ought to be one standard of review or two (the ‘bifurcation’ debate), whether proportionality review incorporates sufficient evaluation of process, whether proportionality should incorporate formal criteria of deference or whether these are assimilated into the balancing process, and the appropriate intensity of proportionality review. On this latter question, a discussion which has regularly and vigorously exercised judicial minds on the UK Supreme Court (‘UKSC’) has been the ‘manifestly without reasonable foundation’ standard (‘MWRF’) used in cases alleging