Essays on the new 'flexible' nature of the constitutional arrangements of the European Union.

1. Introduction
Gráinne de Búrca and Joanne Scott
2. Flexibility within a Metaconstitutional Frame: Reflections on the Future of Legal Authority in Europe
Neil Walker
3. "Old Flexibility": International Agreements Between Member States of the EU
Bruno de Witte
4. Flexible Models: External Policy and the European Economic Constitution
Marise Cremona
5. Closer Co-operation and the Court of Justice
Carole Lyons
6. Flexibility in the Geographical Scope of EU Law
Jacques Ziller
7. Differentiation Within the "Core"? The Case of the Internal Market
Gráinne de Búrca
8. EMU and the Catch-22 of EU Constitution-making
Filip Tuytschaever
9. Flexibility and Social Policy
Catherine Barnard
10. Flexibility and European law: A Labour Lawyer's View
Miguel Rodriguez-Piñeiro Royo
11. Finding Space for Closer Co-operation in the Field of Culture
Stephen Weatherill
12. Flexibility, "Proceduralization", and Environmental Governance in the EU
Joanne Scott
13. Flexibility and Co-operative Law
Karl-Heinz Ladeur
14. Flexibility and Models of Governance for the EU
Eric Philippart and Monika Sie Dhian Ho
15. Constitutionalism and Flexibility in the EU: Developing a Relational approach
Jo Shaw

Gráinne de Búrca is Professor of Law, Fordham Law School, New York.
Joanne Scott is Professor of European Law at University College, London.