Unravelling horizontal direct effect in EU law: the case of the fundamental right to paid annual leave between ‘myth’ and ‘practice’

It is rather trendy to talk about the ‘horizontal effect’ of fundamental rights in a society where the dividing line between public and private power is increasingly blurred. However, as soon as one tries to define the exact meaning of horizontal effect and its conditions, several issues swiftly arise. This article explores the past, the present, and the future of the horizontal direct effect in the European Union (EU) legal order, by focusing on the application of this doctrine to the fundamental labour rights today protected in the Charter of fundamental rights. Most notably, with the approaching of the fifth birthday of Bauer and Max-Planck, by looking at the case of the fundamental right to paid annual leave under Article 31(2) of the Charter, this article aims at unravelling the actual meaning of the conditions for the horizontal direct effect of the EU fundamental rights and the actual perimeter of this direct effect. Although the effectiveness of minimum labour rights mandatorily enhanced by this case law should be welcomed, it is argued that the doctrine of the horizontal direct effect of EU fundamental rights seems still stuck between being a proper constitutional doctrine and a mere type of direct effect. It is also claimed, first, that horizontal direct effect is not a unitary phenomenon in EU law. In spite of the continuity in the ECJ’s technical reasoning, there is indeed a striking contrast between the language of ‘perfect equalisation’ of the Charter to the treaties and its actual approach to the assessment of the horizontal direct effect of fundamental (labour) rights. The ECJ’s case law analysis on the fundamental right to paid annual leave will prove this point. Secondly, it is suggested that horizontal direct effect can be defined as a sui generis, on-call, subsidiary, corollary, and ‘amputee’ doctrine, and we will offer some considerations on each of these features by reference to the Court’s practice under investigation. Thirdly, we suggest that the horizontal direct effect of fundamental (labour) rights relies more on the history and trajectory of the EU regulation of that specific right in the EU legal order rather than on the wording of the Charter’s provision or other technicalities