This report delves into the multifaceted impact of Brexit on the United Kingdom's parliamentary sovereignty and its global business environment. It begins by establishing the historical context of parliamentary sovereignty and its evolution, particularly concerning the UK's membership in the European Union. The report examines how EU membership challenged and altered the traditional understanding of parliamentary authority, citing court decisions like Factortame and Van Gend en Loos to illustrate the supremacy of EU law over national law. Furthermore, it analyzes the effects of Brexit on the economic landscape, including changes in trade environments, competition, and job opportunities. The report then explores the anticipated restoration of parliamentary sovereignty post-Brexit, while acknowledging the complexities and ongoing influence of EU law. It concludes that while Brexit may restore some parliamentary authority, the full restoration of orthodox parliamentary sovereignty remains uncertain due to the lasting impacts of EU legislation and court decisions. The report uses references to relevant academic journals and legal cases.