On July 23, Italy’s Constitutional Court did something unusual. It was facing one of the most contested laws in recent Italian history, a 2025 reform that largely ended its nationality by descent provision overnight.
In Europe, nationality law is usually a matter of national, rather than European, law. But instead of settling the dispute itself, the Italian court referred a question to the Court of Justice of the European Union.
The Court of Justice sits in Kirchberg, the seat of the EU institutions based in Luxembourg. And, in a uniquely European twist, it is most likely Luxembourg, of all the other EU countries, that has the most at stake in the outcome of the case.
We are following this case milestone by milestone. See our Case Tracker to get the latest information as this case goes through each stage in the court process.
A tale of two diasporas
Until last year, millions of the descendants of Italian emigrants who settled across the Americas and beyond could theoretically be considered Italian nationals from birth themselves. This was based on legal traditions that have been in place since the unification of Italy in the 19th century.
Luxembourg’s story runs parallel. During the 19th century, thousands emigrated from the Grand Duchy. Based on legal traditions dating back to the creation of the Grand Duchy, a certain number of these emigrants’ descendants can be considered Luxembourgers by simple fact of the law as well.
As in Italy, the vast majority of these Luxembourgish descendants are not aware of this situation and have never officially registered their nationality.
Luxembourg’s own unregistered nationals
Occasionally, though, they do find out. And in Luxembourg’s case, the result has recently become visible in the country’s own statistics.
In March, RTL reported a striking gap in Luxembourg’s official figures. Between the end of 2024 and the end of 2025, the number of Luxembourgers registered as living in the United States rose from 17,380 to 20,954, an increase of 3,574. Yet Ministry of Justice statistics recorded only 657 people from the United States becoming Luxembourgers that year through naturalization, option or recovery.
In an interview, Justice Minister Elisabeth Margue explained that there are two distinct ways a person can become a Luxembourger. One is through an “act of will,” such as naturalization, option or recovery. The other is directly “by law.”
Article 1 of Luxembourg’s 2017 nationality law provides that the child of a Luxembourgish parent is a Luxembourger. Article 7 provides that birth in the Grand Duchy before a date that advances each year establishes Luxembourgish nationality. Currently, that date falls in 1948.
While the 2017 law provides the current framework, this legal tradition also predates the present law. Successive nationality laws inherited older rules under which nationality passed through the family line, subject to the law applicable at the time of birth across the generations. As such, someone could be born generations after their last ancestor born in Luxembourg and still be born a Luxembourgish national themselves.
This explains much of the statistical gap. Many of the people added to the national register in the US over the last year had contacted a Luxembourg authority for the first time and had the Luxembourgish nationality they held since birth recorded, often together with their children.
What Italy changed
Italy’s laws created a legally similar situation on a larger scale. For generations, its law treated the foreign-born child of an Italian as Italian from birth. A descendant could therefore ask an authority or a court to recognize an existing status, even if the family and the Italian state had not previously documented it. This applied without generational limit, meaning someone could make a claim going back generations to an Italian born ancestor.
In March 2025, Italy changed that premise through an emergency decree that was eventually converted into a law. The new provision dictates that a person born abroad who possesses another nationality is considered never to have acquired Italian nationality, including when the person was born before the reform, unless one of a limited number of exceptions applies.
The wording is important. The law does not simply impose a generational limit for children born in the future. It reaches backward and changes the legal treatment of people who, under the previous framework, would have been considered Italian from birth. The principal protections are for people who had already filed a qualifying administrative or judicial request for recognition of Italian nationality by the March 27, 2025 cutoff, people with a parent or grandparent who held only Italian nationality, and certain people whose parent had resided in Italy for at least two continuous years before their birth.
Italian judges quickly asked whether this was constitutional, and the dispute rose to the Constitutional Court. In April, the Court upheld the reform. Its core argument was this: these people never had their nationality formally confirmed, so it was never legally certain, so nothing real was taken from them. The Court also saw no reason to involve the EU courts.
Six weeks later, it changed its mind on that last point. Italian nationality also carries European citizenship, with the right to live and work anywhere in the Union. And the EU’s own court has long insisted that when a member state strips people of that European status, the consequences for real lives must be weighed. But all of those past cases involved people whose nationality was officially established before being taken away. Whether Europe also protects the national nobody ever registered is a new question. No court has answered it. Now the judges in Kirchberg must.
A reform on the horizon in Luxembourg?
RTL reported that Minister Margue is studying whether it may be time to revisit Luxembourg’s nationality law. All the while, she herself emphasized that any reform during the current legislative term would require consensus and dialogue with the other parties. The 2023-2028 coalition agreement contains no commitment to overhaul the nationality law.
As with any country, Luxembourg’s nationality law has changed over time. The country has undergone three major nationality reforms since the turn of the century. Given that precedent, and that the last edition of the law is now nine years old, it’s only natural that a nationality reform would occur at some point in the not-too-distant future. Any possible reform of Luxembourg’s nationality law would likely require reflection on a large number of factors. But, by the minister’s own public statements, the treatment of how the Luxembourgish nationality passes from one generation to another would likely be one of the main questions under review.
Two debates, one plateau
Luxembourg’s Ministry of Justice sits less than a kilometer from the Court of Justice. Over the coming two years, two similar but distinct debates about the same underlying question may well run side by side on the same plateau.
What the Court has really been asked is whether nationality that exists by law, but was never registered, enjoys European protection. And if a state wants to change such a system, how may it do so in compliance with European law?
The timing is where this becomes concrete. A ruling of this weight will likely arrive between late 2027 and early 2028. If elections are not called sooner, Luxembourg will hold its next legislative elections in October 2028. Whether a nationality reform enters the agenda before then, and in what form, remains to be seen.
If it does, the reform would not only be about questions affecting how nationality passes from one generation to another. But on this particular point, Luxembourg would face a delicate calculation. If it decides to reform its nationality law, and specifically the treatment of people who theoretically possess Luxembourgish nationality, before the Court rules, there is the risk that the judges in Kirchberg could answer differently, opening the door to administrative chaos. If it waits, any eventual reform will be written within whatever frame the Court has drawn.
Either way, part of a very Luxembourgish question, what to do about a truly unknown number of people born abroad who the law already considers Luxembourgish, will be shaped by a case that began in Italy and is argued over the fates of Brazilians and Argentines.
Follow the case: our Picuso Watch tracker shows each of the nine steps between now and the final ruling, updated as they happen. “Picuso” is the fictitious name assigned to the court case, this is a typical EU Court of Justice practice.
Daniel Atz is the founder of LuxCitizenship and StartBrazil.com, and producer of the documentary “Lëtzebuerger an Argentinien.” He writes on citizenship, migration and belonging.
