Taking exercise

The ECJ's judgment in Case C-135/08 Rottmann (Grand Chamber, 2 March 2010) clarifies the powers of member states to make decisions about nationality. The difficulty in this area arises from the fact that the status of citizenship of the European Union is not independently defined, but depends on citizenship of a member state. Article 20 TFEU (Treaty on the Functioning of the European Union, formerly article 17 EC) provides that: 'Every person holding the nationality of a member state shall be a citizen of the Union.' The decision to confer or withdraw nationality rests with each state. And the member states have made it clear that the creation of citizenship of the Union was not intended to detract from this power. Questions of nationality (and thereby of Union citizenship) should be settled, as it was put in a declaration annexed to the Treaty on European Union, 'solely by reference to the national law of the member state concerned'. Rottman is the latest of a number of cases where the full extent of this principle has been tested.

Rottmann was originally an Austrian national. He applied for naturalisation in Germany, and became a German national in 1999 '“ thereby automatically losing his Austrian citizenship. It transpired that he had made deceptive statements in his application for German nationality, as a result of which the German courts considered that it could, under applicable German law, be revoked. But that might leave Rottmann stateless, since his Austrian nationality would not necessarily be re-acquired. If so, Rottmann would lose his status as a citizen of the Union. Could that, the German court wondered, be compatible with EU law?

Inconsistent response

The ECJ's response to this question was somewhat tortuous. On the one hand, it clearly wishes to maintain that the definition of nationality is exclusively a competence of the member states. If one took that statement at face value one might think that the answer was clear: whether or not Rottmann could be deprived of his German nationality would be exclusively a matter for German law. On the other hand, a series of cases (starting with Case C-369/90 Micheletti [1992] ECR I-4239) have held out the prospect that the member states' competence in this field might not be unfettered, but that 'due regard' must be paid to EU law.

To resolve this tension, the ECJ reached for a familiar tool of EU law: the distinction between the existence of a power, and the exercise of that power. Member states enjoy the exclusive power to decide who will enjoy nationality: it is their power alone. But EU law might control the exercise of that power '“ and that control evidently could extend to precluding a decision which would deprive a citizen of the Union of his citizenship. There is not any absolute bar on making a person stateless. It could be acceptable (under EU and international law) in cases where the nationality had been acquired by fraud, but only provided the exercise was proportionate '“ a matter left for the national court to decide.

What, truly, is left of the principle that nationality is decided solely by national law? In reality the ambition of EU law to control the 'exercise' of member state powers in this regard means that nationality law is undoubtedly not the exclusive province of the member states. EU law does define if not the circumstances in which citizenship can be acquired then at least those in which it can be lost. Moreover, it appears to do so quite generally, since the ECJ held that it was not the exercise by Rottmann of his right to move to Germany which brought the case within the ambit of EU law, but simply the consequences which would follow from loss of citizenship. The principle sketched in Micheletti turns out to have teeth.