Recent judgments of the ECJ in the cases Mangold, Kücükdeveci, AMS and Egenberger show that general principles of EU law and provisions of the Charter of fundamental rights of the European Union can have horizontal direct effect. The granting of horizontal direct effect to the Charter is remarkable. Fundamental rights are normally means to protect private individuals vis-à-vis public authorities. Within the international and national legal orders, the horizontal direct effect of fundamental rights is not common.
In this paper this legal institute will be analysed and discussed in relation to the chapter on »Solidarity« of the Charter.
This research is based on the hypothesis that the predominant interest – the primacy of the European Union law over national law – which is pursued by this legal institute does not affect in a disproportionate manner the principle of interinstitutional balance and the principle of legal certainty.