Within the composite European multilevel governance constellation, national agencies occupy a unique position tying together the supranational and national levels. National agencies engage with multiple actors at the supranational and national levels who, based on various public and private interests and despite agency independence, seek to steer the enforcement behaviour of these agencies. On the receiving end, national agencies possess a certain level of discretion, engrained within their independent nature, allowing them to make decisions to shape their course of action, within the boundaries established by their formal institutional design and regulatory competences. Previous research underscores the complex position of national agencies as integral components of the EU multilevel governance system as well as agents navigating the influence of multiple actors. However, it offers a rather simplistic view of the perceptions of national agencies and fails to capture the variety of responses of national agencies can give following steering attempts by supranational and national actors. Furthermore, little is known about what happens when conflicting multilevel steering occurs and how this affects the responses of national agencies. The present paper aims to study two questions. First, how do national agencies respond, i.e., demonstrate specific enforcement behaviour ranging from acquiescent to defiant, when confronted with multilevel steering? And second, what explains these responses? This paper takes inquiry into the European railway sector and two types of national regulatory authorities, i.e., national competition authorities and national safety authorities. The research questions will be examined by building on the framework of Oliver (1991) on strategic responses, using additional theoretical insights to make it fit for national agencies within the composite EU multilevel governance context. The data collection consists of a survey and semi-structured interviews with the relevant national authorities.
