Some recent attitudes to the scope of judicial review in the field of immigration policy represent a sharp contrast with the trends which typify the current renaissance in administrative law. The conspicuous features of modern developments are the range and intensity ofjudicial initiatives in expanding, almost beyond recognition, the parameters within which the exercise of supervisory jurisdiction is warranted in principle. Despite some suggestions to the contrary, it is not altogether satisfactory to regard the revamped notion oferror oflaw as an organising principle which supplants review mechanisms founded on the bedrock of vires; but it is quite evident that the theory of jurisdiction which lies at the root of seminal concepts sustaining the framework of judicial review is in the process of being transformed by contemporary ap roaches. The virtual equation of error of law with jurisdictional excess at any rate in regard to administrative tribunals as distinguished from inferior courts, has dramatically enlarged the scope of judicial review on the ground of jurisdictional fault, especially in the light of radical perceptions of the criteria which are called in aid to identify errors of law.