This article distinguishes between parliamentary sovereignty and parliamentary legislative supremacy. Sovereignty is an abstract concept, focusing on the power to enact and modify the rules which constitute governmental institutions and their relative powers, including the power to make law – referred to as foundational constitutional provisions. Legislative supremacy focuses on the relative power of institutions to enact legislation which is legally recognised as the highest source of law in a particular legal system. It argues that, whilst the Westminster Parliament is not and should not be sovereign, it should have legislative supremacy. Parliament is not sovereign as sovereignty is shared between Parliament and the courts. Whilst both Parliament and the courts may assert the ability to change foundational constitutional provisions, both need to agree to these changes for them to be effective. Parliament needs to have legislative supremacy to ensure that it is not able to change these provisions alone. This provides greater legitimacy for foundational constitutional provisions in the UK which lacks a codified constitution enacted in a manner different from the making of ordinary legislation.
Alison Young (Wed,) studied this question.