When Member States to apply the Charter of Fundamental Rights of the European Union?

The contribution deals with the obligation of the Member States to apply the Charter of Fundamental Rights of the European Union in specific cases, that is when they are implementing Union law or when they act within the scope of the Union law. The author analyzes these essential terms in the light of the case law of the Court of Justice which provides their extensive interpretation. Moreover, this paper analyzes the scope of application of fundamental rights as a part of general principles of the Union law and their possible horizontal applicability arising from the Kücükdeveci judgment. Further, the contribution mentions effects of the Protocol No. 30 on the application of the Charter of Fundamental Rights of the European Union to Poland and to the United Kingdom which is considered to be an interpretative instrument for the application of the Charter and not an opt-out.