(en) Any assessment of the achievements of the Charter should also have regard to its interaction with the other international instruments protecting fundamental rights. The Convention occupies a central position in this respect, since national judges must comply with it whenever they apply Union law. Coherence between the Convention and the Charter is therefore of great importance, since at the end of the day it is for the Strasbourg Court to assess compliance with fundamental rights in any given case. In view of this reality the Union legislature provided for a twofold mechanism for checking coherence between the Charter and the Convention: an internal one, based on Article 52(3) of the Charter, which is complemented by an external one, based on scrutiny by the European Court of Human Rights, as provided for by Article 6(2) TEU. So far, the internal control mechanism has worked well as far as the content of fundamental rights is concerned. The same cannot be said when it comes to the methodology applied to those rights. The case-law of the CJEU indeed looks as if Article 52(3) related only to the content of the rights concerned and not to their methodology. This generates methodological discrepancies which give rise to either lower protection levels than under the Convention or legal confusion. These deficiencies of the internal control mechanism call for the setting up of the external mechanism.
Callewaert, J. (2021). Vingt ans de coexistence entre la Charte et la Convention européenne des droits de l’homme: un bilan mitigé. In Emmanuelle Bribosia; Cecilia Rizcallah; Sébastien Van Drooghenbroeck (ed.), The EU Charter turns 20 / La Charte UE a 20 ans. Larcier. https://hdl.handle.net/2078.5/114286