Under What Conditions Do Migrants’ Rights Defenders Mobilize the Court of Justice of the EU?

While legal mobilization in the United States or before the European Court of Human Rights has been studied extensively, scholars have only recently turned their attention to legal mobilization before the Court of Justice of the European Union (Conant et al. 2017). In particular, this research focuses on what are the conditions under which the preliminary reference mechanism (267 TFEU) can be used as a tool for civil society’s participation. The answer is not obvious, since the Court of Justice has been defined at the same time as “the most effective supranational judicial body in the history of the world” (Stone Sweet 2004) and as “hostile to collective action” (Harlow and Rawlings 1992). This means that the Court of Justice, on the one hand, with its high enforcement rate, represents a great opportunity for civil society actors; on the other hand, the Court also represents a great challenge: collective actors hardly have access to it, because of its restrictive legal standing rules and the high cost of the proceedings. Moreover, access to the Court is structurally unbalanced: according to its procedural rules, EU Member States’ governments can always intervene as third-parties in the proceedings, while only one party represents migrants’ interests. To understand the conditions that make legal mobilization before the CJEU concretely possible, my research departs from the classic court-centric approach and focuses on the national context where the proceedings arise, by combining a legal and empirical analysis. Specifically, this paper draws on the findings of three case studies on legal mobilization for migrants' rights in the UK, the Netherlands, and Italy. For each case study, I conducted interviews with migrants’ rights supporters and national judges, and I have investigated the national political and procedural framework, gaining valuable insights into the concrete dynamics of litigation. The comparison of the three case studies suggests that legal mobilization before the Court of Justice occurs only when three particular conditions are met: collective actors provide EU law expertise; the collective and individual grievances overlap; and there is an open EU "legal opportunity structure" (Hilson, 2002). To further corroborate these findings, I tested them against two cases of ‘non-mobilization’, confirming that, when one of the conditions is missing, mobilization does not occur. In conclusion, the outcome of this research offers an innovative understanding of EU litigation, shedding light on the limits and potential of the preliminary reference mechanism as a tool to transform EU law from below.