European Arrest Warrants and Prison Conditions: The CJEU Clarifies What Happens When Surrender Is Refused

4 June 2026

The Court of Justice of the European Union has clarified an important question concerning European Arrest Warrants issued for the enforcement of prison sentences: what happens when surrender is refused because detention in the issuing Member State would expose the requested person to a real risk of inhuman or degrading treatment?

In its judgment of 4 June 2026 in Joined Cases C-722/23, Rugu and C-91/24, Aucroix, the Court held that refusal of surrender on fundamental-rights grounds should not result in the custodial sentence remaining unenforced.

Instead, the executing Member State must take active steps to obtain recognition of the foreign judgment and, where the relevant legal conditions are satisfied, enforce the sentence within its own territory.

The judgment is particularly relevant to Greek extradition and European Arrest Warrant practice because one of the two cases concerned an EAW issued by the Greek authorities for the enforcement of a five-year prison sentence.

The background to the cases

The joined cases arose from two European Arrest Warrants examined by the Belgian courts.

The first warrant had been issued by the Romanian authorities against a Romanian national residing in Belgium for the enforcement of a four-year sentence for trafficking in human beings.

The second warrant had been issued by the Greek authorities on 9 March 2016 against a Belgian national for the enforcement in Greece of a five-year custodial sentence.

In the Greek case, the Belgian court refused surrender after concluding that the requested person’s mental-health difficulties, combined with the conditions in which he was likely to be detained in Greece, would expose him to a risk of violation of his fundamental rights under Articles 3 and 5 of the European Convention on Human Rights.

The issue was therefore no longer whether the person should be surrendered to Greece. The Belgian courts had already refused surrender.

The question was what should happen to the Greek sentence after that refusal.

Could Belgium simply decline to execute the EAW, leaving the sentence unenforced? Could the Belgian court apply the optional ground for non-execution under Article 4(6) of Framework Decision 2002/584 and order the sentence to be served in Belgium? Or did EU law require a different procedure?

The Court of Justice addressed these questions by examining the relationship between:

• Framework Decision 2002/584 on the European Arrest Warrant; and

• Framework Decision 2008/909 on the mutual recognition and enforcement of custodial sentences.

Refusal of surrender on fundamental-rights grounds

The European Arrest Warrant system is founded on mutual recognition and mutual trust between EU Member States.

As a general rule, an executing judicial authority must recognise and execute a warrant issued by another Member State. Refusal is permitted only in the situations recognised by EU law.

Fundamental rights nevertheless remain an essential limit.

Article 1(3) of Framework Decision 2002/584 states that the EAW system does not modify Member States’ obligation to respect fundamental rights and fundamental legal principles under Article 6 of the Treaty on European Union.

Under the established case law of the Court of Justice, surrender must not take place where there are substantial grounds for believing that the requested person would face a real risk of inhuman or degrading treatment, contrary to Article 4 of the Charter of Fundamental Rights of the European Union.

A prison-conditions challenge normally requires a two-stage assessment.

First, the executing court must examine whether objective, reliable, specific and properly updated material demonstrates systemic or generalised deficiencies in detention conditions, or deficiencies affecting particular groups or particular facilities in the issuing Member State.

Secondly, the court must assess whether the individual requested person would face a real risk of prohibited treatment in the particular conditions in which that person is likely to be detained.

Where such a risk cannot be excluded after the exchange of information with the issuing judicial authority, execution of the EAW may ultimately be refused.

The new judgment does not weaken that protection. A person cannot be surrendered to conditions that expose them to a real risk of inhuman or degrading treatment.

The Court’s concern was what follows after surrender has lawfully been refused.

Fundamental-rights protection must not lead to impunity

The Court distinguished two different grounds on which an EAW for enforcement of a sentence may not be executed.

The first is refusal based directly on fundamental-rights protection under Article 1(3) of Framework Decision 2002/584.

The second is the optional ground under Article 4(6), which allows an executing Member State to refuse surrender where:

• the EAW was issued for enforcement of a custodial sentence;

• the requested person is staying in, is a national of or resides in the executing Member State; and

• that State undertakes to enforce the sentence under its domestic law.

Article 4(6) serves a particular objective. It allows a sentence to be served in the country where the person has sufficient social and family connections, thereby facilitating social rehabilitation while avoiding impunity.

The Court held that these two grounds cannot simply be combined after the event.

Where surrender has already been refused because it would violate fundamental rights, the executing court cannot subsequently treat that same refusal as though it had been based on Article 4(6).

The legal basis for the refusal remains Article 1(3).

Nevertheless, the refusal does not release the executing Member State from its responsibility to prevent the sentence from remaining unenforced.

The Court held that the executing Member State must use the separate mechanism established by Framework Decision 2008/909 for the recognition and enforcement of custodial judgments.

The executing State must take the initiative

Framework Decision 2008/909 normally enables the Member State that imposed a custodial sentence to transmit its judgment and a standard certificate to another Member State so that the sentence can be recognised and enforced there.

Ordinarily, the initiative lies with the sentencing State.

However, Article 4(5) of the Framework Decision allows the executing State to request the sentencing State to forward the judgment and certificate.

The Court held that where an EAW has been refused because surrender would expose the person to inhuman or degrading treatment, the executing Member State must use this possibility.

It must request, on its own initiative, that the issuing Member State transmit:

• the judgment imposing the custodial sentence; and

• the certificate required under Framework Decision 2008/909.

The purpose is to make possible the recognition and enforcement of the sentence in the executing State.

The Court therefore rejected a passive approach. A Member State cannot simply refuse surrender on fundamental-rights grounds and take no further action, where the result would be that a final sentence is not served anywhere.

The official summary of the judgment states that a Member State refusing an EAW because of detention conditions must take all possible steps to ensure that the sentence is enforced within its own territory.

Is the issuing State required to transfer the judgment?

The judgment also recognises an important procedural difficulty.

A request by the executing State under Article 4(5) does not formally oblige the issuing State to transmit the judgment.

The issuing State retains a degree of discretion.

However, the Court held that this discretion must be exercised consistently with the principle of sincere cooperation and the effectiveness of judicial cooperation in criminal matters.

The issuing State must take account of the fact that refusing to transfer the judgment could leave the sentenced person unpunished and undermine the objective of social rehabilitation.

In practical terms, the two States must cooperate to prevent the operation of the EAW and sentence-recognition systems from reaching a dead end.

The judgment therefore establishes obligations on both sides:

• the executing State must actively request the judgment;

• the issuing State must consider that request in good faith and with due regard to preventing impunity.

Is the sentenced person’s consent required?

Transfer of a custodial judgment to another Member State may, in principle, require the sentenced person’s consent.

There are, however, important exceptions.

Consent may not be required where the judgment is transferred:

• to the Member State of which the sentenced person is a national and in which that person lives; or

• to the Member State to which the person fled or otherwise returned after the foreign proceedings or conviction.

In the Greek EAW case, the requested person was a Belgian national residing in Belgium. The Court indicated that his consent might therefore not be required, although the final assessment remained for the Belgian court.

This is important in practice. A requested person cannot necessarily prevent domestic enforcement of the foreign sentence merely by refusing consent after surrender has been refused.

What the judgment means for Greece

The judgment has a dual importance for Greek courts and authorities.

Greece as the issuing Member State

Where Greece issues an EAW for enforcement of a Greek sentence and another Member State refuses surrender because of detention conditions or an individual health risk, the Greek sentence does not simply cease to have effect.

The executing State must seek transfer of the Greek judgment under Framework Decision 2008/909.

Greek authorities may then be required to transmit:

• the final judgment;

• information concerning the sentence already served;

• the standard certificate;

• any additional information required for recognition.

A refusal to cooperate could result in the sentence remaining unenforced and would be difficult to reconcile with the principle of sincere cooperation.

At the same time, the possibility of foreign enforcement does not remove the need for Greek authorities to provide precise, reliable and individualised information concerning detention conditions when requested during the EAW proceedings.

Where the challenge concerns the requested person’s health, authorities may need to address:

• the proposed detention facility;

• available psychiatric or medical treatment;

• continuity of medication;

• hospital access;

• individual accommodation needs;

• measures capable of reducing the alleged risk.

Generic assurances may not be sufficient.

Greece as the executing Member State

The same principle applies when Greek courts refuse to execute an EAW issued by another Member State.

If a Greek court refuses surrender for enforcement of a sentence because the person would face a real risk of prohibited treatment, Greece may be required to initiate the procedure for recognising and enforcing the foreign sentence domestically.

This will require coordination between:

• the Greek judicial authority that refused surrender;

• the Ministry of Justice;

• the competent authorities of the issuing State;

• the authorities responsible for recognising and enforcing foreign custodial judgments.

The decision therefore connects EAW litigation with the separate field of transfer and recognition of criminal judgments.

A defence lawyer handling the EAW must consider not only whether surrender can be prevented, but also the possible consequences of domestic enforcement of the sentence.

Refusal of surrender is not equivalent to cancellation of the sentence

The judgment highlights a distinction that is often misunderstood by requested persons.

A successful objection to surrender does not necessarily eliminate the underlying foreign conviction.

The court executing an EAW normally decides whether the requested person should be transferred to the issuing State. It does not act as an appellate court reviewing the correctness of the foreign conviction.

Where surrender is refused because of detention conditions, the reason concerns the place and manner in which the sentence would be served—not necessarily the validity of the conviction itself.

The sentence may therefore remain capable of:

• recognition in the executing State;

• enforcement in that State;

• adjustment where permitted by the applicable recognition rules;

• deduction of time already spent in custody.

A successful human-rights challenge can protect the person from detention in conditions contrary to Article 4 of the Charter without creating immunity from the sentence.

Practical consequences for the defence

The ruling changes the strategic assessment of EAW cases involving sentence enforcement.

Before relying on detention conditions as a ground for refusal, the defence should examine the likely consequences if the sentence is transferred to Greece or another executing State.

Relevant questions include:

• Can the foreign judgment legally be recognised?

• Is it final and enforceable?

• Was it rendered in absentia?

• Were the defendant’s procedural rights respected?

• Is the offence also punishable under the law of the executing State?

• Can the duration or nature of the sentence be adapted?

• How much time has already been served?

• Could limitation or another domestic enforcement obstacle apply?

• Is the person’s consent required?

• Which prison conditions would apply in the executing State?

• Would domestic enforcement be more or less favourable than surrender?

The defence may also need to coordinate parallel proceedings in the issuing State, such as:

• an appeal;

• an application to reopen an in absentia conviction;

• an application for suspension of the sentence;

• a request for alternative enforcement;

• a challenge to the continuing validity of the EAW.

The EAW hearing should therefore not be treated as an isolated proceeding.

A more integrated European enforcement system

The judgment reflects a broader direction in EU criminal cooperation.

Fundamental-rights protection remains capable of preventing surrender in exceptional cases. At the same time, refusal of surrender should not automatically produce impunity.

The Court has connected three principles:

1. protection from inhuman or degrading treatment;

2. mutual recognition of criminal judgments;

3. effective enforcement of final custodial sentences.

The result is neither automatic surrender nor automatic release from punishment.

Where detention in the issuing State would violate fundamental rights, the European system must seek a lawful alternative: enforcement of the sentence in the State where the person is located, provided the requirements of Framework Decision 2008/909 are satisfied.

Conclusion

The judgment in Rugu and Aucroix confirms that fundamental-rights objections remain a genuine limit on European Arrest Warrant surrender.

However, it also makes clear that a successful prison-conditions challenge does not ordinarily extinguish the sentence underlying the warrant.

Where surrender for enforcement of a custodial sentence is refused because of a real risk of inhuman or degrading treatment, the executing Member State must actively pursue recognition and domestic enforcement of that sentence.

For lawyers handling European Arrest Warrant cases in Greece, the decision requires a wider defence strategy.

It is no longer sufficient to ask whether surrender can be refused. Counsel must also consider:

• whether the foreign judgment can subsequently be recognised in Greece;

• how the sentence may be adapted or enforced;

• whether separate proceedings should be brought in the issuing State;

• how detention conditions and medical risks should be documented;

• whether refusal of surrender genuinely improves the requested person’s legal position.

The judgment therefore strengthens fundamental-rights scrutiny, while simultaneously ensuring that such scrutiny does not create an unintended route to non-enforcement of final criminal judgments.

This article is intended for general informational purposes and does not constitute legal advice. European Arrest Warrant proceedings depend on the circumstances of the individual case, the purpose of the warrant and the law of the issuing and executing Member States.

This article is for informational purposes only and does not constitute legal advice. It does not create a lawyer-client relationship. Readers should consult qualified counsel in the relevant jurisdiction before taking action based on the information provided. All statutory references are current as of July 2026 and may be subject to subsequent amendment.

Sources

1. Council Framework Decision 2002/584/JHA of 13 June 2002 on the European Arrest Warrant and the surrender procedures between Member States.
2. Council Framework Decision 2008/909/JHA of 27 November 2008 on the application of the principle of mutual recognition to judgments imposing custodial sentences or measures involving deprivation of liberty.
3. Charter of Fundamental Rights of the European Union, Articles 4, 47 and 48.
4. European Convention on Human Rights, Articles 3, 5 and 6.
5. Joined Cases C-722/23, Rugu and C-91/24, Aucroix, Judgment of the Grand Chamber, 4 June 2026.
6. Press Release No 78/2026, Court of Justice of the European Union, A Member State that refuses to execute a European arrest warrant because of the conditions of detention in the issuing Member State must take all possible steps to ensure that the custodial sentence is enforced in its own territory.
7. Joined Cases C-404/15 and C-659/15 PPU, Aranyosi and Căldăraru.
8. Case C-216/18 PPU, Minister for Justice and Equality (LM / Celmer).
9. Joined Cases C-354/20 PPU and C-412/20 PPU, Openbaar Ministerie.
10. Case C-128/18, Dorobantu.
11. Case C-699/21, E.D.L.