There are many reasons to seek French citizenship, from the practical such as shorter passport queues and the end to residency card requirements to a more emotional sense of wanting to be a part of your country of residence.

But a big reason is security – the knowledge that you won’t be kicked out of the country if you screw up your paperwork and you can come and go as you please.

However, in certain circumstances nationality can be revoked.

Within two years 

The first two years of your French citizenship contain an extra clause that allows the public prosecutor to contest the registration of a declaration of nationality. This must be done within two years of the date that citizenship is granted and applies in two cases;

• If the legal conditions for French citizenship are not met – such as length of residency, for example. This is usually dealt with before citizenship is granted. But say, for example, the person handling your dossier had made a mistake or missed something in your dossier that makes you ineligible for citizenship, that can be corrected and the citizenship revoked 
• If, within two years of citizenship being granted, it is discovered that the recipient lied or committed fraud to gain French citizenship. For example if you fake up a French language test certificate or claim to be employed when you are not. The most common cases of fraud relate to citizenship granted through marriage – if a marriage is dissolved within 12 months of citizenship being granted then fraud may be suspected. This doesn’t mean that all people whose marriages break down need to worry, it is simply a possible cause for investigation and the prosecutor would need to prove that your marriage was never a genuine marriage to begin with.

In order to strip a person of citizenship, the prosecutor must prove their case and you have the chance to put forward your defence.

If proved, the citizenship is annulled, and – legally – was never awarded because the decree specific to your naturalisation is cancelled.

Crucially, however, rights acquired before the publication of the decree remain valid. So having your citizenship annulled doesn’t mean that you no longer have the right to live in France, if you were legally resident with a residency permit before the citizenship was granted.

Within 15 years 

Once two years have passed, your citizenship cannot be cancelled, even if it is later discovered that you lied on your application.

However there are several circumstances in which people may be stripped of French nationality. 

• If they have been convicted of a crime or an offence constituting undermining the fundamental interests of France;
• If they have been convicted of a crime or an offence constituting an act of terrorism;
• If, while in public office, they are convicted of a crime or an offence constituting interference with public administration. For example, infringement of individual freedom, discrimination;
• If they have not complied with the obligations arising from national service;
• If they have acted for the benefit of a foreign State, incompatible with being French.

It is also possible for a person’s nationality revoked if the following two conditions are applicable:

• If they are are active in a foreign army, public service or international organisation of which France is not a member, and;
• They refuse to stop this activity despite a government order.

There is a timeline here too – the forfeiture of citizenship can only be invoked for acts committed before acquiring French nationality; or within 10 years of acquiring French nationality, extended to 15 years in the event of an attack on the fundamental interests of the Nation or an act of terrorism.

Being convicted of an ‘ordinary’ crime such as burglary or assault would not result in your losing citizenship.

The controversial immigration law that passed Parliament at the end of December 2023 includes the possibility of stripping dual nationals of their French citizenship if they are convicted of intentional homicide against anyone in a “position of public authority,” such as police officers, soldiers, judges, or administrative officials, full details of this new law (and its timeline for application) are yet to be published.

Protections

No person can be left stateless under French law – this means that only those who have dual nationality can be stripped of French citizenship. Therefore people whose home country does not allow dual nationality and who gave up their original nationality to become French cannot lose their French citizenship.

Anyone who is French by birth cannot lose their French nationality.

In 2018 then-president François Hollande proposed a law allowing convicted terrorists who had been born in France to be stripped of their citizenship if they also had nationality of another country, but he was forced to back down after widespread outrage.

Even if people meet the criteria to lose their citizenship, there are additional limits on the powers of the state to strip a person of their French nationality. All three of the following conditions must apply:

• The person must also be a national of another State;
• The person must ‘behave’ like the citizen of this State (this is usually taken to mean having a genuine connection to this State such as speaking the language or having previously lived there)
• The person must have committed acts contrary to the interests of France.

You have the legal right to contest being stripped of citizenship, and only the Conseil d’Etat can remove a person’s French citizenship.

The future

So that’s what the law says at the moment – but governments change and laws change too, and dual nationals have no specific constitutional protection in France.

During World War I, a law allowed people from enemy countries such as Germany, Austria and Hungary to be stripped of their French nationality.

The Vichy government, in power during World War II, stripped some 15,000 people, including 7,000 Jews, of their French nationality. In many cases these were people who had lived in France for decades and had been naturalised many years earlier.

One of those stripped of their French citizenship was the Belarus-born painter Marc Chagall – he was lucky enough to be able to flee to the USA and survived the war. Many others did not.

The next presidential election is in 2027 and far-right leader Marine Le Pen is widely considered to be a likely contender.

In her 2012 and 2017 election campaigns, Le Pen proposed banning dual nationality – meaning that people could only become French citizens if they renounce the citizenship of their birth country.

She dropped that plan in her 2022 election campaign, to the reported surprise of many in her party, but the current legal framework of France would not prevent her from implement such a policy, provided she won an election first, of course.