This book offers a legal understanding regarding the core elements of SGEI (Services of General Interest), and of how the post-Lisbon constitutional framework on SGEI affects the application of the EU market rules by the EU Court of Justice, including procurement rules, to public services. It is built up of three parts, namely Part I: No Exit from EU Market Law for Public Services, Part II: SGEI as a Constitutional Voice for Public Services in EU Law, and Part III: The cost of loyalty, the relationship between EU procurement and state aid legislation on social services and the Treaty rules...