There is currently a good deal of disagreement concerning the constitutional justification for judicial review in English law. The ultra vires doctrine holds that review is simply a function of legislative intention. In contrast, a number of commentators argue that administrative law is a body of judge-made common law which is unrelated to the will of Parliament. The truth lies somewhere between these two poles.
The traditional ultra vires doctrine is unsatisfactory because, inter alia, it is unrealistic to assert that judicial review constitutes nothing more than the implementation of legislative intention. However, the attempt of some commentators to exclude intention from the justification for review is equally deficient since this is an affront to the sovereignty of Parliament. By locating the interpretative methodology of ultra vires within its proper constitutional setting and by recognising the importance of the rule of law to the process of statutory construction, it is possible to articulate an explanation of judicial review which is consistent with Parliament's legislative supremacy while avoiding the shortcomings of the traditional ultra vires principle (notably its inability satisfactorily to explain the derivation of the grounds of review; the courts' treatment of ouster clauses; the development of administrative law across time, and the extension of judicial review to non-statutory powers).