This book illuminates the process and substance of transnational regulation of labour in a global economy. Transnational labour regulation, a central feature of the European social model, engages the 27 Member States of the European Union, and is of potential importance to the rest of the world. The book analyses the attempts at transnational regulation of temporary agency work through the social dialogue between trade unions and employers' organisations at European level and the subsequent -- and so far fruitless -- EU legislative process. These two processes of transnational labour regulation, and their interaction, until now have been largely invisible. The book also highlights distinctive features of Member States' national regulation as they interacted with the debates on EU transnational labour regulation. It further explores the overlap between regulation of temporary agency work and the EU's regulation of transnational trade in services, the subject of the Directive on services in the internal market. Finally, it draws lessons from the experience of regulation of temporary agency work at national and European levels for transnational labour regulation in general.