(Series Information) European Papers - A Journal on Law and Integration, 2017 2(1), 223-229 | European Forum Insight of 26 March 2017 | (Table of Contents) I. Introduction. - II. The Danish Supreme Court's reasoning. - III. The 'selective' supremacy of EU law according to the Danish Supreme Court: is it time to reaffirm Costa v. ENEL?. - IV. The horizontality of the EU Charter of Fundamental Rights. - V. Conclusion. | (Abstract) The present Insight focuses on the reception by the Danish Supreme Court (judgment of 6 December 2016, no. 15/2014, DI acting for Ajos A/S v. The estate left by A.) of the Court of Justice decision in the Dansk Industri case (judgment of 19 April 2016, case C-441/14 [GC]). Instead of disapplying a national provision which was found by the Court of Justice to be inconsistent with the general principle of non-discrimination of grounds of age, the Danish Supreme Court stresses that the Law of Accession of the Kingdom of Denmark to the European Union does not cover general principles of EU law and the national provision cannot be disapplied. The selective approach of the Danish Supreme Court raises a number of concerns which this Insight highlights: first, a clear misunderstanding regarding the functioning of general principles of EU law; second, a violation of the duty of sincere cooperation and the relate doctrine of supremacy of EU law; third, an arguable assessment of the effects of the Charter of Fundamental Rights.