The scope of EU fundamental rights protection and the influence of the Charter of Fundamental Rights on this scope is a much discussed topic among EU constitutional lawyers. As is well-known, the recognition of fundamental rights as part of the general principles of EU law by the Court is not new. Already in the cases of Stauder and Internationale Handelsgesellschaft, handed down in 1969 and 1974 respectively, the Court recognized fundamental rights as part of the general principles of EU law. It did so to anticipate challenges to the primacy of EU law by national constitutional courts and the Court therefore took great care in stressing the autonomous nature of EU fundamental rights protection. This means that the Court has maintained authority in determining the content of EU fundamental rights protection and thus remained the ultimate interpreter of EU law. However, before the coming into force of the Treaty of Lisbon, there was no EU catalogue of rights formally binding on the EU as such. Rather, the Court drew inspiration from international treaties and national constitutions, whilst at the same time maintaining the autonomy of the EU rights standard. With the coming into force of the Lisbon Treaty the Charter of Fundamental Rights has also become formally binding on the EU. This means there now is a binding catalogue of rights at the EU level.
A contentious issue is whether the Charter of Fundamental Rights alters the scope of the EU fundamental rights standard laid down in previous case-law of the Court. In its case law, the Court has held that fundamental rights recognized as general principles of EU law apply not only to the acts of the EU institutions but also to the acts of Member States in certain circumstances. Generally, Member States have to act in accordance with fundamental rights recognized at the EU level ‘whenever they act within the scope of EU law’. In the case-law of the Court this includes at least two situations. First, Member States are bound by the EU rights standard where the implement and enforce EU law. Second, the Member States are also bound by the EU rights standard where they derogate from EU law provisions (see cases such as Schmidberger, and ERT). However, when precisely a Member State acts within the ‘scope of EU law’ is not entirely clear. The dividing line between situations within the scope and those outside the scope of EU law often appears arbitrary, as was pointed by AG Sharpston in the case of Zambrano.