He is author of The Political Police in Britain (1976) and Secrecy and openness in the EU (1999, Kogan Page). For Statewatch he has edited: Statewatching the new Europe: a handbook on the European state (1993), The Europol Convention (1995), Researching the European state: a critical guide (1996) and Key texts on justice and home affairs in the European Union: From Trevi to Maastricht: 1976-1993 (1997).