The Court of Justice's Principle of Effectiveness and its Unforeseeable Impact on Private Law Relationships

Abstract

The principle of effectiveness is a legal figure that the Court of Justice of the EU has developed in order to ensure that EU law actually takes effect in the legal orders of the Member States. Consequently, national private law or civil procedural law may not be applied at all in a given private law relationship, or they may be interpreted differently from what the contracting parties expected. This mainly applies to provisions that the party in breach of the contract would benefit from. Where, in contrast, parties act in good faith, the Court of Justice balances the effectiveness of EU law against the principle of legal certainty, and good faith can also be considered by the national courts when they do or do not interpret national law in the light of EU law so that overall the ‘invasion’ of the Court in private law relationships seems justified.