## Facts

- The German Federal Labour Court referred six questions in Joined Cases C-397/01 to C-403/01 for a preliminary ruling.
- The reference asked how an EU directive should influence the construction of conflicting German legislation.
- Queries focused on whether the obligation of consistent interpretation applied equally to provisions enacted before and after the directive.
- The national court also asked whether domestic interpretative techniques had to be used even when statutory wording seemed to exclude a directive-compliant reading.
- The draft does not specify the directive’s identity, the exact domestic provisions, or full party names beyond “Pfeiffer”.

## Issues

1. Does the duty of consistent interpretation oblige national authorities to construe all domestic provisions—regardless of enactment date—in line with the directive?
2. What limits, particularly the principle nulla poena sine lege, restrict that interpretative duty?
3. Must courts and administrative bodies exhaust every interpretative method recognised by domestic law to achieve conformity with the directive?

## Decision

- Every state organ applying law within the directive’s field must, so far as possible, interpret each domestic rule—whether predating or post-dating the directive—in the light of the directive’s wording and purpose.
- The duty of consistent interpretation cannot found new criminal offences or increase existing criminal penalties, preserving legal certainty and the legality principle.
- National authorities must employ every interpretative tool sanctioned by their legal order, ceasing only where the national wording cannot sustain a directive-compliant meaning (contra legem).

## Legal Principles

- The principle of consistent interpretation binds all Member State authorities when applying law touched by an EU directive.
- The obligation is temporally neutral; it attaches equally to national measures enacted before and after the directive.
- Legal certainty and the prohibition of retroactive or aggravated criminal liability mark the outer limits of directive-conform interpretation.
- Domestic bodies must deploy all interpretative methods allowed by national law to secure conformity, stopping only when the text cannot bear the EU-consistent meaning.

## Conclusion

The Court of Justice ruled that all national authorities must exploit every permissible interpretative method to align domestic law with an EU directive, irrespective of the national provision’s age, yet without overstepping statutory language or generating or intensifying criminal liability.

Pfeiffer (Joined Cases C-397/01, C-398/01, C-399/01, C-400/01, C-401/01, C-402/01 and C-403/01) [2004] ECR I-8835