Municipalities tend to enter co-operations with other municipalities. The democratic legitimacy of inter-municipal co-operation, however, is rather low. Representative democracy provides insufficient solutions to this problem. Research question is: How can the democratic legitimacy of local government in inter-municipal co-operations be effectively increased? The study aims to answering this question by having a conceptual contribution to the policy debate on inter-municipal co-operations. Secondly, it will compare real cases of inter-municipal co-operations in which democratic legitimacy is founded in diverse democracy concepts. This will be done in an international comparative study (comparing cases in Germany, Belgium, and England). In the organisation of the project much attention will be paid to the involvement of practitioners and the dissemination of knowledge.