This book provides a comprehensive overview of the party finance regime at the level of the European Union. Based on an in-depth analysis of the interaction between European political parties and their institutional environment, it shows how the Europarties have coped with and altered the funding rules. The book explains why increasing party subsidies have been made available, and why considerable differences exist in how Eurosceptic and pro-European parties have used their EU funding. It also examines how party finance reform at the EU level has been at the centre of party competition, by demonstrating how the rules were strategically changed to benefit some European parties over others. Considering the strong democratic aspirations that lay at the origins of the finance regime, the book explores its consequences for party democracy and the rule of law in Europe. This book is valuable for scholars working on the European Parliament, Eurosceptic parties, EU decision-making, (European) party politics and political finance.