On July 18th, Advocate General Cruz Villalón delivered a fascinating opinion in a case that could very well keep quite a number of scholars interested in EU fundamental rights law busy for a while. In Association de Médiation Sociale not yet available in English as far as I can see) the Court is confronted with a set of fundamental questions. First, whether the workers’ right to information and consultation within the undertaking as enshrined in Article 27 of the Charter and implemented through Directive 2002/14 establishing a framework for informing and consulting employees in the Union can be applied in a legal dispute between two private parties, i.e. on its potential horizontal effect. Second, this also implies discussing – for the first time explicitly – the difference between rights and principles enshrined in Articles 51 (1) and 52 (5) of the EU Charter of Fundamental Rights. In particular, this requires shedding light on the notion of implementation of principles, as Article 52 (5) speaks of principles being ‘judicially cognisable’ only in the interpretation of their implementing acts and the ruling on their legality. Third, the act with which the Union implemented the principle in the present context is a directive, which again raises the question as to the limits to the effect of directives in a legal dispute between private parties, as has already caused problems in well-known cases like Mangold and Kücükdeveci. As the opinion is already quite comprehensive, I’ll keep my comments to the minimum to not try our readers’ patience.