Intergovernmental Relations in the UK provides a timely and up-to-date analysis of a turbulent decade in British politics and presents a fascinating case study of intergovernmental relations and territorial power in a devolved unitary state. As over time a widening range of powers has been transferred from the Westminster Parliament to the devolved legislatures in Scotland, Wales and Northern Ireland, intergovernmental relations have become increasingly important to deal with the corresponding overlaps of legislative and fiscal authority. However, leaving the European Union has exposed the weakness of the intergovernmental architecture and challenged the functionality of the UK’s multilevel polity. Until now, the question of how powerful the devolved administrations really are has not been satisfactorily answered. The author uses insights from comparative studies of federations to develop a systematic account of shared rule and intergovernmental relations. This book examines how informal institutions and practices can provide political influence beyond formal structures, with reference to an extensive range of institutions, practices, policies and political decisions. Unlike other studies focused predominantly on the state of the Union, this volume points to the interplay between conflict and cooperation, and demonstrates that the proclaimed ‘break-up of the Union’ is accompanied by efforts to integrate the different jurisdictions. This book will be of interest to scholars and postgraduate students of comparative politics, political systems, multilevel governance, regional and federal studies, British politics and public administration. It will also appeal to politicians, government advisers, civil servants and other practitioners who seek a better, more nuanced understanding of the UK’s multilevel constitution and politics, and the nature of intergovernmental relations in the UK.