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 acquired Austrian nationality in 1995 and renounced her former Turkish nationality in 1996 as a condition for retaining the Austrian nationality. In 2018 the Austrian authorities declared that she has no longer been an Austrian national since 1997 as it appeared that she voluntarily re-acquired her Turkish nationality at that time, which is a ground for automatic loss of Austrian nationality. The Court set aside the determination of loss of Austrian nationality as it did not carry out a proportionality test on the basis of the Tjebbes judgment.
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.
The applicant was issued an assurance that she will acquire Austrian nationality if she renounced her former Serbian nationality, which she did. However, after the assurance was issued the applicant committed a number of administrative offences, leading to the assurance being withdrawn after the renunciation of the former nationality has already taken place, resulting in the applicant's statelessness. The Court emphasised the constitutional significance of a letter of assurance of acquisition of nationality, and sided with the applicant.
In order to acquire Austrian nationality, the applicant renounced her Turkish nationality in 1997. Over a decade later it came to light that she has re-acquired Turkish nationality in 1998, which according to Austrian law resulted in automatic loss of the Austrian nationality. She renounced her Turkish nationality again in 2009, but in 2010 the Austrian authorities confirmed that she was no longer Austrian since 1998. The Court found that this was not in violation of Austria's obligation to avoid statelessness since the applicant's statelessness was not caused by a decision of the Austrian authorities.