## Facts

- Ms. Kücükdeveci was dismissed by her employer after more than ten years of service.
- German law permitted periods of employment before the age of 25 to be disregarded when calculating severance pay.
- This statutory rule adversely affected younger employees.
- Ms. Kücükdeveci argued that this provision contravened the principle of non-discrimination on grounds of age under Directive 2000/78/EC.
- The dispute was between Ms. Kücükdeveci and a private employer, precluding direct reliance on the directive.

## Issues

1. Whether a national law allowing employment before age 25 to be excluded from severance calculations constitutes age discrimination under EU law.
2. Whether a directive lacking direct effect in disputes between private parties can nevertheless influence national courts’ interpretation of domestic law.
3. Whether general principles of EU law, such as non-discrimination, can be independently invoked in horizontal disputes.

## Decision

- The Court held that national courts must interpret domestic law, as far as possible, to comply with directives and the principle of non-discrimination on grounds of age.
- The CJEU found that, despite the lack of direct effect of Directive 2000/78/EC in horizontal disputes, the general principle of non-discrimination could be relied upon.
- The Court established that the duty of sincere cooperation (Article 4(3) TEU) obliges national courts to ensure conformity with EU law, including general principles, in private disputes.
- By relying on the principle of consistent interpretation, national courts must set aside national rules incompatible with EU general principles.

## Legal Principles

- General principles of EU law, such as non-discrimination, have legal effect in both vertical and quasi-horizontal relationships.
- The duty of sincere cooperation obliges national courts to interpret national law in conformity with EU directives and the principles they reflect.
- The principle of consistent interpretation can render certain directives indirectly enforceable between private parties, even absent direct effect.
- National courts are required to ensure the effective protection of rights conferred by EU law, including fundamental rights articulated in directives.

## Conclusion

The CJEU in Kücükdeveci clarified that national courts must disapply national legislation conflicting with EU general principles, such as non-discrimination on grounds of age, by interpreting domestic law in line with relevant directives, even in disputes between private parties, thereby confirming the quasi-horizontal effect of such EU law principles.

Kücükdeveci v Swedex GmbH & Co KG (Case C-555/07) [2010] ECR I-365