## Facts

- Germany enacted an approval statute authorizing ratification of the Treaty on European Union (Maastricht Treaty) and adopted a constitutional amendment facilitating participation in European integration, including revised Article 23 of the Basic Law.
- Multiple individuals, including Manfred Brunner and certain German members of the European Parliament, filed constitutional complaints challenging the approval statute and the constitutional amendment.
- The complaints argued that the Treaty transferred extensive sovereign powers—especially in economic and monetary policy—thereby diminishing Bundestag authority and voters’ democratic influence.
- The complainants also alleged that European decisionmaking would weaken fundamental-rights protection and that the new integration clause in the Basic Law was itself unconstitutional.
- The Federal Constitutional Court found most complaints inadmissible; it accepted one complaint in part, limited to whether the approval statute violated the right to vote for the Bundestag (Article 38 of the Basic Law), read with the democracy principle and the eternity clause.

## Issues

1. Whether approving the Maastricht Treaty unconstitutionally reduced Bundestag powers and citizens’ democratic influence, violating the right to vote (Basic Law art. 38) in conjunction with the democracy principle protected by the eternity clause (art. 79(3)).
2. Whether the constitution imposes enforceable limits on transfers of sovereign powers to European institutions, including whether the Constitutional Court may review European acts for exceeding conferred competences (ultra vires).
3. Whether the Maastricht Treaty created a European federal state incompatible with continued German statehood, or instead an association of states compatible with the Basic Law.

## Decision

- The Court dismissed most complaints as inadmissible, including challenges directed at the constitutional amendment enabling integration.
- On the merits of the admissible challenge, the Court upheld the approval statute and found the Maastricht Treaty compatible with the Basic Law.
- The Court held that the Treaty did not violate Article 38 because the Bundestag retained powers of substantial significance and the democratic minimum required by the constitution remained intact.
- The Court characterized the European Union as a Staatenverbund (association of sovereign states), not a federal state supplanting German sovereignty.
- The Court declared it would review whether European institutions act within the competences transferred to them and that ultra vires European acts would not be binding in Germany.

## Legal Principles

- The right to vote for the Bundestag (Basic Law art. 38) protects not only formal electoral participation but also a minimum level of democratic self-determination, including meaningful influence over the exercise of public authority through the Bundestag.
- Transfers of sovereign powers to a supranational entity are constitutionally permissible if democratic legitimation remains secured, primarily through Member State parliaments, supplemented by the European Parliament.
- The democracy principle, protected against constitutional amendment by the eternity clause (art. 79(3) in conjunction with art. 20), limits the extent of competence transfers; the Bundestag must retain tasks and powers of substantial significance.
- The European Union, under the Maastricht framework, is an association of states grounded in conferred powers; Member States remain the source of sovereignty and can transfer only limited competences.
- The Constitutional Court reserves authority to review whether European acts remain within conferred competences (ultra vires review); acts exceeding those competences lack domestic binding force.

## Conclusion

The Court permitted Germany’s ratification of the Maastricht Treaty while treating democratic self-determination as constitutionally protected against excessive competence transfers and asserting domestic ultra vires review to ensure European institutions remain within conferred powers.


Brunner v. Federal Republic of Germany (Maastricht Treaty Case), 89 BVerfGE 155 (BVerfG 1993)