Held, (1) the grounds upon which an executing judicial authority could refuse to execute a European arrest warrant derived solely from Council Framework Decision 2002/584/JHA, and even then only in strictly interpreted, exceptional, cases. However, the provision of Belgian law in the present case, which had the same scope as article 1(3) of the Framework Decision, did not establish a ground for non-execution which did not stem from the Framework Decision. Accordingly, an executing judicial authority did not have the power to dismiss a European arrest warrant on the basis of a ground for non-execution which arose solely from the law of the executing member state, and not from the Framework Decision. However, the judicial authority could apply a national provision which allowed the execution of a European arrest warrant to be refused where it would lead to an infringement of a fundamental right enshrined in EU law, provided that the scope of that provision did not go beyond the ambit of article 1(3) of the Framework Decision (judgment, paras 72–74, 78, 79, operative part, para 1).

(2) The EU legislature entrusted each member state with the designation of the judicial authorities competent to issue European arrest warrants, and the ability to assess their jurisdiction in that respect. Although it was for the executing judicial authority to ensure that the European arrest warrant had indeed been issued by a judicial authority within the meaning of article 6(1) of the Framework Decision, the executing authority could not verify that the issuing authority had jurisdiction to issue such a warrant nor refuse to execute that warrant where it considered that that was not the case (judgment, paras 85–87, 89, operative part, para 2).

(3) Although the executing judicial authority could not verify the jurisdiction of the issuing judicial authority, it was responsible for assessing the merits of any requested person’s allegation that they would be tried, in the issuing member state, by a court that lacked jurisdiction for that purpose contrary to article 47 of the Charter. That assessment involved a two-step process whereby the executing judicial authority had to determine: (a) whether there was objective, reliable, specific and properly updated information demonstrating that there was a real risk of infringement, in the issuing member state, of the right to a fair trial guaranteed by article 47, in particular, on account of systemic or generalised deficiencies in the operation of the judicial system of the issuing member state or deficiencies affecting the judicial protection of an objectively identifiable group of persons to which the requested person belonged; and (b) to what extent any deficiencies identified were liable to have an impact on the proceedings to which the requested person would be subject and whether, having regard to that person’s personal situation, the nature of the offence charged and the factual context in which the warrant was issued, there were substantial grounds for believing there was a real risk that that person’s right to a fair trial would be infringed if they were surrendered to the issuing member state. The trust that was thus conferred on the courts of the issuing member state was the corollary of the principle that the member states themselves were responsible for guaranteeing the observance of the requested person’s fundamental rights. The Framework Decision, read in the light of the Charter, could not be interpreted in such a way as to call into question the effectiveness of the principle of judicial co-operation between the member states. Accordingly, article 1(3) of Framework Decision 2002/584, read in conjunction with article 47 of the Charter, meant that the executing judicial authority deciding whether to surrender a requested person could not refuse to execute the European arrest warrant on the ground that that person was at risk of being tried by a court in the issuing member state which lacked jurisdiction unless: (a) there were deficiencies in the issuing member state’s judicial system or the protection of requested persons which would deprive them of the right to review the jurisdiction of the criminal court that would try them; and (b) there were substantial grounds for believing that that court lacked jurisdiction to hear the proceedings. The fact that the person concerned was able, before the courts of the issuing member state, to rely on their fundamental rights in order to challenge the jurisdiction of the issuing judicial authority and the European arrest warrant issued was not relevant (judgment, paras 101, 102, 106, 110, 114–116, 119, 120, operative part, para 3).

(4) To ensure that the operation of the European arrest warrant system was not brought to a standstill and that there was effective co-operation between the member states in criminal matters, the issuing and executing judicial authorities had to make full use of the instruments provided for in articles 8(1) and 15 of Framework Decision 2002/584 to foster the mutual trust on which that co-operation was based. Accordingly, in order to comply with the principle of sincere co-operation, the executing judicial authority could not refuse to execute a European arrest warrant on the ground that the requested person was at risk, following their surrender to the issuing member state, of being tried by a court lacking jurisdiction for that purpose, without having first requested the issuing authority to provide supplementary information concerning its applicable jurisdictional and procedural rules (judgment, para 131–134, 136, operative part, para 5).

(5) Framework Decision 2002/584 did not preclude the issuing of several successive European arrest warrants against a requested person with a view to obtaining their surrender by a member state after the execution of a first warrant had been refused by that member state, provided that the execution of a new warrant did not result in an infringement of article 1(3) of the Framework Decision and provided that the issuing of the latter warrant was proportionate (judgment, paras 140, 143, 146, operative part, para 6).