When deciding a dispute, a national court in the EU can ask the CJEU to make a preliminary ruling on the interpretation or validity of an EU legal act. According to the ECtHR, if a national court of last instance has rejected a request by parties in the proceedings for a preliminary ruling to be made, this may infringe the ECHR. Firstly, where EU Member States (who are all ECHR Contracting Parties) have transferred competence to the EU (not an ECHR Contracting Party), the ECtHR applies a presumption that the EU provides human rights protection equivalent to the ECHR so that the transfer is ECHR compatible. In this regard, the preliminary ruling is an important controlling mechanism, so that failing to refer may rebut this presumption. Secondly, where a national court refuses to make a preliminary reference requested by a party without providing reasons, this may infringe Article 6(1) ECHR.