Research team

The effectiveness of directives in horizontal situations: a reassessment in the post exclusion/substitution-dichotomy era. 01/11/2023 - 31/10/2025


Union directives cannot be invoked by a private individual against another private individual before a national court, thus stated the Court of Justice of the EU ('the Court') in Marshall (Case 152/84). About fourty years later, the confusion brought about by subsequent case law of the Court has made the determination of the contours of the effectiveness of directives in horizontal situations, as well as the consequences and underlying rationale thereof, "a task fit only for masochists" (Dougan 2007). The obscurity surrounding the effectiveness of directives in horizontal situations carries great practical consequences. Whether one can invoke a directive in a horizontal situation (i.e. against another private individual) directly determines the remedies one can rely on to mitigate violations of Union law before the national courts. The proposed research will employ i.a. novel, groundbreaking, case law by the Court in order to unravel precisely when directives can be effective in horizontal situations. Furthermore, it will develop original evaluation criteria to assess whether or not the conditions imposed by the Court on that effectiveness can be considered due limitations. Should the conditions on the effectiveness of directives in horizontal situations as derived from the Court's case law not meet the developed criteria, the proposed research will inquire how the undue restrictions can be mitigated.


Research team(s)

Project type(s)

  • Research Project