An Austrian national by birth transferred his residence to Germany and naturalised as a German national. The naturalisation in Germany had the effect, in accordance with Austrian law, of causing him to lose his Austrian nationality. The German authorities later withdrew the naturalisation with retroactive effect, on the grounds that the applicant had not disclosed that he was the subject of a criminal investigation in Austria on account of suspected serious fraud, and that he had thus obtained German nationality by deception. The Court held that it is not contrary to EU law for a Member State to withdraw nationality obtained by deception, even if it results in losing EU citizenship, so long as the decision observes the principle of proportionality. Observance of the principle of proportionality requires the person concerned to be afforded a reasonable period of time in order to try to recover the nationality of their Member State of origin.
The applicant received assurance of obtaining Austrian nationality if she renounces her Estonian nationality. After the renunciation, it appeared that the applicant committed two administrative offences related to her driving, which in addition to the eight she committed previously were considered as an indication of her no longer fulfilling the public order requirement for naturalisation. This resulted in the withdrawal of assurance of obtaining Austrian nationality, leaving the applicant stateless.