The UK’s decision to withdraw from the European Union has triggered much debate on the legal status of UK nationals living in an EU-27 Member State and EU citizens living in the UK. Fearing a Hard Brexit, politicians, NGOs as well as academics have suggested diverging options for ensuring that all EU citizens who, prior to Brexit-day have exercised their free movement rights, will be able to retain their residence and equal treatment rights.

The various ideas and proposals all seem to be based on the presumption that Brexit will imply loss of EU citizenship for UK nationals. This is logical. The wording of Article 20 TFEU – “[E]very person holding the nationality of a Member State shall be a citizen of the Union” - makes clear that to be an EU citizen one must a Member State national. Loss of a Member State nationality implies automatic loss of this privileged status. When a Member State withdraws from the EU its nationals become third country nationals.

Earlier this year, however, an Amsterdam court expressed doubts about this reading of Article 20. This court was faced with a case that was initiated by UK nationals living in the Netherlands who claimed that the Dutch State and/or the city of Amsterdam had to take measures to ensure that they could continue to enjoy EU citizenship rights after Brexit.

Referring to case law of the Court of Justice, and Rottmann in particular, the Amsterdam court observed that EU citizenship now constitutes an own autonomous source of rights and that decisions implying loss of Member State nationality must be proportional. In the court’s view, it is far from sure that loss of national citizenship implies loss of EU citizenship. The Amsterdam stated its intention to ask the Court of Justice whether a hard Brexit indeed implies that UK nationals will become ‘ordinary’ third country nationals.

In the end, however, no preliminary question was send to Luxembourg. It is not clear to me why the Amsterdam court thought that UK nationals might keep EU citizenship after Brexit. It may very well be that EU citizenship has evolved to become a fundamental status that may constitute an autonomous source of EU rights, and that the Treaty demands that EU citizens can genuinely enjoy EU citizenship rights. From that, however, no conclusion can be drawn about a possible retention of EU citizenship itself. The Dutch court suggests that EU citizenship can possibly be retained because of Rottmann.

In this ruling the Court of Justice held that Member States must, before taking a decision withdrawing “their” nationality, consider the consequences of such a decision for the person concerned as regards the loss of the rights he/she enjoys as an EU citizen. It is hard to understand, however, why or how the Court’s line of reasoning in Rottmann can be extended to situations in which a Member State national loses his/her nationality as a result of the decision of his/her Member State to step out of the Union. A decision to withdraw nationality in individual cases and a decision to withdraw as an entire State from Union are not in any serious manner comparable. The entire reasoning of the Court was clearly geared towards the specific individual situation in which Mr Rottmann found him. It simply does not make much sense to draw from this reasoning conclusions for the entirely different situation of Brexit in which millions could lose EU citizenship as a result of collective decision adopted in accordance with their own democratic rules to exit the EU.

Article 20 TFEU makes it patently clear that EU citizenship is derivative in nature. In Rottmann nor in any other ruling did the Court cut through EU citizenship’s exclusive and absolute link with Member State nationality. From existing case law one, arguably, can only draw one logical conclusion: for UK nationals, Brexit implies loss of EU citizenship.

Of course, (some) UK nationals might hope for an activist Court that in a next case will be willing to change its position. The Court is well advised, however not to do so if it does not wish to be accused of acting contrary to the Treaty drafters’ goals. In Maastricht the drafters made it patently clear that it is the Member States that decide on nationality and thus on who possesses EU citizenship. In Lisbon, by including Article 50 in the TEU, and thus by ordering the EU to negotiate and conclude an agreement with the exiting Member State governing the arrangements for withdrawal, the Treaty drafters made it clear that a possible retention of EU citizenship and the rights linked to it is a task for the political EU institutions, not for the Court. The entire structure of Article 50 TEU implies that it is up to a Member State to withdraw from the Union without there being any limitation imposed by EU law as to the reasons for the withdrawal, how this decision is taken or the extent to which that Member State takes into consideration the interests of its own nationals. If a Member State decides to exit the EU, and thus to strip their nationals of EU citizenship, it is perfectly entitled to do this. The EU, including its highest court cannot and should not alter this.