In its recent Bauer judgment, the Court of Justice of the European Union established that the right to paid annual leave enshrined in the Charter of Fundamental Rights of the European Union can be invoked in a worker / private employer context (horizontal direct effect). In Bauer, the CJ took a firm position in view of attributing, in the future, horizontal direct effect to other provisions of the Charter, a constitutional development of great relevance with concrete practical implications.
In the very recent Bauer judgement, the Grand Chamber of the Court of Justice of the European Union (CJ) established that the right to paid annual leave can be invoked by a worker against its “private” employer (horizontal direct effect).
In one of the two disputes underlying this judgment, a widow asked to its late husband’s (private) employer an allowance in the amount of EUR 3 702,72 corresponding to the 32 days of outstanding paid annual leave which her husband had not taken at the time of his death.
According to the national (German) law, the right to paid annual leave is lost in the event of the worker’s death. However, the Working Time Directive (Directive) precludes national law which, like German law, determines that such right is lost in the event of the worker’s death. In other words, the Directive was not correctly transposed.
Since the legal act in question is a Directive, its provisions could not be invoked by a private party against another private party. In this judgment, the CJ also concluded to be impossible to provide a harmonious interpretation of the national law vis-à-vis the Directive.
The solution found was to attribute horizontal direct effect to article 31(2) of the Charter of Fundamental Rights of the European Union (Charter) in the part where it enshrines the right to paid annual leave.
The reasoning underpinning this interpretation contains a number of criteria to consider, namely a) the status of the relevant right as an “essential principle of EU social law”; b) the writing of this right in “mandatory terms”;  and c) the “mandatory and unconditional in nature [of the existence of the right], […] not needing to be given concrete expression by the provisions of EU or national law”. 
Considering that the right to paid annual leave is not the only right in the Charter to meet these criteria, in Bauer the CJ takes a firm position in view of attributing, in the future, horizontal direct effect to other provisions of the Charter, a constitutional development of great relevance with concrete practical implications.
In the field of labour law, for instance, with the Bauer judgment, an analysis of the relevant secondary law is no longer sufficient to comprehend the whole of the framework regulating private parties’ labour relations. Indeed, in some cases, the lawyer must assess i) if the Charter is applicable and ii) what substantive impact such application might have.