In this paper we develop a comparative study of the different regulatory frameworks governing interest groups and non-governmental organizations (NGOs) at the national and regional level in Spain from transition to democracy to present. Our goal is to explore the similarities and differences in the regulatory frameworks in Spain and four Comunidades Autónomas –Andalucía, Catalonia, Galicia, the Basque Country—. We argue that the existing regulatory framework, characterized by large fragmentation and dispersion of norms about the internal structure, functions and financing of interest organisations, and the lack of regulation of interest groups access to the governmental and parliamentarian arenas, has contributed to reinforce the role of traditional interest organisations like business groups, professional organisations, and trade unions, which occupy a privileged position in the policy making process vis-á-vis other organisations like advocacy groups and NGOs. To illustrate this argument, we use the databases created by the Spanish Policy Agendas project about interest groups access to the parliamentarian, and governmental arena for the last decades.
