The recent judgment of the Court of Justice of the European Union (CJEU) of 1 August 2025 in case C-600/23, Royal Football Club Seraing, marks a profound change in sports arbitration.

In this case, the CJEU establishes that national courts of the Member States can and must review rulings of the Court of Arbitration for Sport (CAS) when there is a risk that they may infringe European public policy — fundamental principles of EU law such as the freedoms of movement, competition law, and fundamental rights — even if those awards have been confirmed by the Swiss Federal Tribunal.

The dispute originated from FIFA’s sanction against the Belgian club Seraing for third-party ownership contracts, confirmed by the CAS and the Swiss court. The CJEU ruled that res judicata cannot prevent judicial review if there are possible breaches of EU law, especially since sports arbitration is not always freely accepted but imposed by organisations such as FIFA.

The Court declared that res judicata cannot be attributed to a CAS award within an EU Member State if it has not first been subjected to effective judicial scrutiny by a competent national court, with the possibility of referring preliminary questions to the CJEU.

The CJEU distinguishes between commercial (voluntary) and sports (imposed) arbitrations, noting that mandatory clauses imposed by bodies like FIFA limit effective judicial protection if no ex post review by national courts is allowed.

Effective judicial protection (Art. 47 CFR). A system granting res judicata status and automatic evidentiary value without judicial review violates the fundamental right of access to an impartial judge. A national court must be able to fully review the award’s compliance with EU law and, if necessary, refer a preliminary question.

The ruling strengthens the primacy of EU law over arbitral decisions. This judgment obliges national courts to disapply domestic rules or sports regulations that prevent such review. It also limits the scope of review to compliance with European public policy, without re-examining the entire case. Finally, it acknowledges the risk of duplicated proceedings and divergent interpretations among Member States, which will require uniform criteria.

The ruling means greater protection for athletes and clubs but also brings challenges: possible slowing of proceedings, tension with the autonomy of sports arbitration, and the need to coordinate oversight between national courts and the Swiss court. The success of this new framework will depend on balancing the efficiency of arbitration with the legal guarantees of EU law.