Modernising Unreasonableness

Abstract

This essay is a doctrinal examination of Hu v Immigration and Protection Tribunal. That case was a recent decision of Palmer J in which he developed a new test for the ground of unreasonableness in judicial review. The test is based on inferring an error of law as the cause of an unreasonable administrative decision. The new test has the advantage of being clearer and less tautological than the words used by Lord Greene in Associated Provincial Picture Houses v Wednesbury Corporation. The essay examines Hu through the window of recent New Zealand High Court authorities, as well through several early authorities that articulated the unreasonableness standard. The analysis identifies that Hu provides useful clarity as a test for unreasonableness in the narrow circumstances where an error of law has led to an unreasonable decision. However, it is not a universal test for unreasonableness, which has many causes other than an error of law. It is concluded that care is required to both maintain the doctrinal integrity of the new test and to ensure that other types of inquiry are used when factual circumstances demand a different approach. The essay examines whether the new test has been applied with the strictness required to maintain consistency with the original error of law doctrine. It is concluded that care is needed to avoid inferring an error of law too readily, or there is a risk of crossing the process merits review boundary. That is inconsistent with the fundamental legal principles that provide a constitutional basis for judicial review. A related question is addressed regarding how Hu can support variable intensity review, given the test represents a fixed standard of unreasonableness. It is concluded that if the intensity of review is increased using unstructured contextual approaches alongside the Hu test, then that creates problems by introducing uncertainty and inconsistency into the judicial assessment