Judicial review in the UK: constitutional balance, parliamentary sovereignty, and the rule of law in the twenty-first century

This thesis examines the constitutional balance between the executive, Parliament, and judiciary, focusing particularly on the tension between parliamentary sovereignty and the rule of law within the evolving framework of judicial review. It analyses how the scope of judicial review has expanded substantially over the past five decades, most notably since the millennium, extending beyond traditional boundaries to encompass areas previously considered immune from judicial scrutiny, and parliamentary legislation under the Human Rights Act 1998. The research addresses whether this expansion constitutes legitimate constitutional evolution or represents unwarranted judicial encroachment into the democratic sphere. The thesis contends that the expansion of judicial review reflects a significant yet principled and evolutionary rebalancing of constitutional relationships rather than a revolutionary shift or simple power transfer. It demonstrates that both common law developments and statutory changes, particularly under the HRA, have enabled courts to exercise enhanced oversight of executive action whilst respecting parliamentary sovereignty. This expanded judicial role has neither resulted in judicial supremacy nor diminished Parliament's ultimate legislative authority, — parliamentary sovereignty and the rule of law mutually reinforced throughout. Employing doctrinal methodology, the study examines statutes, case law, and legal principles to trace judicial review's development and assess its constitutional implications. It analyses how judicial review's scope has evolved across justiciability, standing rules, remedies, and substantive review standards under the HRA. The thesis specifically examines landmark cases such as GCHQ, Belmarsh, and Miller/Cherry, illustrating how courts have asserted authority and reconfigured the balance of power. It also critically evaluates the Judicial Review and Courts Act 2022, arguing that it challenges orthodox approaches to unlawful acts' legal status and may enhance ouster clauses' effectiveness. The thesis concludes that judicial review's expansion has occurred within constitutional constraints and with careful regard for democratic legitimacy, fostering more robust constitutional accountability whilst preserving parliamentary sovereignty.