Where a Member State refuses surrender because the requested person faces inhuman or degrading detention conditions in the issuing State, the matter does not end there. The executing State must then do everything within its power to have the custodial sentence enforced on its own territory — on its own initiative, without any request from the issuing State. The route is not Article 4(6) of the Framework Decision on the European arrest warrant, but Framework Decision 2008/909/JHA.
The background
The Belgian Court of Cassation referred two cases to the Court of Justice, which were joined. They concerned a Romanian and a Belgian national, both resident in Belgium. European arrest warrants had been issued against them by Romanian and Greek judicial authorities respectively, in each case for the enforcement of final custodial sentences.
The Belgian courts of appeal refused to execute the warrants: in Romania and Greece the persons concerned would face a risk of inhuman or degrading treatment because of the detention conditions there. That raised the question which every fundamental-rights refusal poses — what becomes of the final sentence? The Court of Cassation asked whether the Belgian judicial authority may, or indeed must, enforce those sentences in Belgium itself in order to prevent the convicted persons from going unpunished.
The ruling
By judgment of 4 June 2026 the Grand Chamber held: the executing State must. A State that refuses surrender because of a risk of a breach of fundamental rights under Art. 1(3) FD 2002/584/JHA is required to take every step available to it so that the custodial sentence is enforced on its own territory.
The reasoning
First: Article 4(6) is not the route. That optional ground for refusal — declining surrender of a resident in exchange for taking over enforcement — cannot be invoked in addition to a mandatory ground for refusal. A State refusing surrender over detention conditions is not at the same time deciding under Art. 4(6) FD 2002/584/JHA; the two grounds cannot be combined.
Second: the route runs through Framework Decision 2008/909/JHA on the mutual recognition of custodial sanctions. The judicial authority of the executing State must approach the issuing authority on its own initiative and request transmission of the judgment together with the certificate; it must then initiate the steps required for recognition and enforcement. The consent of the sentenced person is not required in the cases covered by Art. 6(2) FD 2008/909/JHA.
Third: the issuing State is placed under an obligation too. Such a request does not oblige it actually to transmit the judgment — Art. 4(5) FD 2008/909/JHA makes that explicit. But it must exercise its right to withhold transmission in a manner that still allows effective cooperation between the authorities responsible for criminal matters; it has to avoid paralysing the operation of the European arrest warrant and of the mutual recognition of judgments. The basis for this is the duty of sincere cooperation under Art. 4(3) TEU.
Throughout, the decisive consideration is the objective in Art. 3(2) TEU: the area of freedom, security and justice must not mean that final sentences come to nothing merely because surrender is ruled out on fundamental-rights grounds. Fundamental-rights protection remains untouched — it merely shifts the place of enforcement.
What this means in practice
For defence work in Germany the judgment changes the direction of the proceedings. Obtaining a refusal of surrender under Section 73 IRG, because detention conditions in the issuing State fall short of European minimum standards, does not free the client from the sentence — it frees them from the foreign prison. The sentence itself survives and moves into enforcement assistance under Sections 84 et seq. IRG.
That is not a setback; in many constellations it is precisely the outcome sought. For a requested person living in Germany with family, work and a permanent address, enforcement at home is as a rule the far better result than surrender: German prison law applies, together with German standards for relaxations of the regime and for suspending the remainder of the sentence on probation. Added to that is the adaptation of the sanction where the foreign sentence is incompatible with German law in duration or nature.
Anyone who factors that outcome in from the outset conducts the case differently — not as an all-or-nothing fight over surrender, but as a decision about which law governs my client's sentence, and in which country it is served.
In EAW proceedings I examine both levels from the outset: the detention conditions in the issuing State — and what enforcement in Germany would actually look like. Since this judgment the second level is no longer a side issue but the foreseeable consequence of success in the surrender proceedings. Turning to it only after the refusal means giving away the options that the enforcement-assistance procedure offers.
Citation: ECJ (Grand Chamber), judgment of 4 June 2026 — Joined Cases C-722/23 (Rugu) and C-91/24 (Aucroix).
Source: Full text and press release No 78/2026 at curia.europa.eu. Reference from the Belgian Court of Cassation (Cour de cassation).
Context: The ruling follows the line of case law on detention conditions as an obstacle to surrender. See OLG Schleswig on Polish detention conditions and BVerfG on Romania's assurance. On the procedure generally: European arrest warrant and Enforcement of foreign judgments.