## Facts

- Italian authorities granted State aid to Lucchini, a steel producer.
- The European Commission declared this aid incompatible with the internal market under EU competition law and ordered its recovery.
- Lucchini challenged the Commission’s decision in Italian courts, initially succeeding, with the aid not recovered.
- Following a preliminary ruling from the CJEU, the Italian courts ultimately upheld the Commission’s decision.
- The core issue arose when a prior Italian court judgment, which was res judicata, seemed to preclude recovery of the unlawful State aid.

## Issues

1. Whether national principles of res judicata can prevent the recovery of State aid deemed unlawful under EU law.
2. Whether the supremacy of EU law requires national courts to disregard res judicata if it obstructs the effective enforcement of EU law.
3. How national courts should balance the principle of legal certainty from res judicata with the obligation to enforce EU competition law.

## Decision

- The CJEU recognized the importance of res judicata but determined that the principle cannot obstruct the application of EU law.
- National courts are required to disapply national procedural rules, including res judicata, if they prevent recovery of unlawful State aid ordered by the Commission.
- The Court held that the supremacy and uniform application of EU law take precedence over national res judicata rules in such circumstances.

## Legal Principles

- The supremacy of EU law requires disapplication of any national rule, even if procedural or based on res judicata, that could impede effective enforcement of EU law.
- Legal certainty and finality from res judicata are important, but cannot prevent application of directly effective EU law, particularly regarding the recovery of State aid found incompatible with the internal market.
- The Lucchini ruling affirms national courts’ duty to set aside rules that conflict with EU law’s effectiveness, a principle established in Costa v ENEL.

## Conclusion

The Lucchini judgment established that national courts must disregard res judicata where it would thwart the enforcement of EU competition law, ensuring the supremacy and full effectiveness of EU law within Member States’ legal systems.

Lucchini v Ministero dell'Industria (Case C-119/05) [2007] ECR I-6199