With the rise of direct-democratic instruments, the relationship between popular sovereignty and the rule of law is set to become one of the defining political issues of our time. This important and timely book provides an in-depth analysis of the limits imposed on referendums and citizens' initiatives, as well as of systems of reviewing compliance with these limits, in 11 European states. Chapters explore and lay the scientific basis for answering crucial questions such as 'Where should the legal limits of direct democracy be drawn?' and 'Who should review compliance with these limits?' Providing a comparative analysis of the different issues in the selected countries, the book draws out key similarities and differences, as well as an assessment of the law and the practice at national levels when judged against the international standards contained in the Venice Commission's Guidelines on the Holding of Referendums. Presenting an up-to-date analysis of the relationship between popular sovereignty and the rule of law, The Legal Limits of Direct Democracy will be a key resource for scholars and students in comparative and constitutional law and political science. It will also be beneficial to policy-makers and practitioners in parliaments, governments and election commissions, and experts working for international organisations.