This an updated edition of an authoritative textbook that places the law in its context. It examines Brexit, referendums, evolving devolution and dramatic political events of 2019 and their impact on the traditional understanding of the Westminster Constitution. It also analyses the two recent constitutional decisions of the Supreme Court. 'Alison Young's new edition of Turpin and Tomkins is a hugely welcome addition to the teaching resources in public law. By placing legal materials in their broader political and constitutional context the book provides a highly accessible and absorbing approach to the subject. It combines the study of basic ideas with a lucid account of their application to a wide range of practical issues.' T. R. S. Allan, Professor of Jurisprudence and Public Law, University of Cambridge