Parliamentary Sovereignty and the Inconsistency of Ultra Vires

Abstract

Parliamentary sovereignty and judicial review can only be reconciled, ultra vires theorists say, if judicial review principles are taken to be authorised by Parliament. While this argument was vigorously debated around the turn of the millennium, it continues to have traction among academics and senior judges today. This article takes stock by returning to ultra vires and surfacing a critical ambiguity at the heart of the doctrine. Its supporters tell us that ultra vires is logically necessary in a system recognising parliamentary sovereignty, and that judges should not abandon it. Yet if ultra vires is abandoned, what are the consequences for parliamentary sovereignty? Two readings of the argument are available. On one reading, parliamentary sovereignty continues to obtain. This generates a logical inconsistency: ultra vires must be true because the system recognises parliamentary sovereignty, but in that same system it could be abandoned by the judges and therefore false. On another reading, to abandon ultra vires does mean to abandon parliamentary sovereignty. But this reading is inconsistent with the evidence-apartheid South Africa, a key case study and the ultra vires theorists' exemplar, where the ultra vires doctrine was definitively repudiated and yet parliamentary sovereignty continued to obtain. Either way, inconsistency afflicts the ultra vires doctrine.

Keywords: judicial review, parliamentary sovereignty, ultra vires