A speck of France in the Indian Ocean has become the latest battleground over the laws on immigration.
A French possession since 1841, the tiny island of Mayotte is now a département or county of the Republic which means, in theory, that the same rules apply there as in the Moselle or Maine-et-Loire, or anywhere else in France.
But the territory’s difficult experience of mass immigration is pushing President Emmanuel Macron’s government to abandon the sacrosanct Frenchprinciple of equality for all.
Visiting the island at the weekend, Interior Minister Gérald Darmanin announced that the automatic right to French citizenship by virtue of birth on the island is to be rescinded.
A constitutional change to this effect is now to be pursued by the government. Crucially the end of “birthplace citizenship” would apply only to the island of Mayotte – not to France as a whole.
But therein lies the rub. For different reasons, both the left and right of French politics see the reform as problematic.
The left says it is a breach of the Republican principle of universality, and opens the door to a citizenship based on racial origin.
The right says that changing the rules for Mayotte are fair enough, but it is in France as a whole that “birthplace citizenship” needs to be abandoned.
The droit du sol – right of the soil, also known as jus soli – is the legal notion that a person born on the territory of a nation automatically becomes a citizen of that nation. Its opposing idea is jus sanguinis – right of blood which confers citizenship only on the children of citizens.
For many, particularly on the left, the droit du sol is an important marker, confirming France’s status as a beacon of humanist values.
In fact, strictly speaking, the droit du sol is not an automatic right in France, as it is for example in the US where a birth certificate is enough to get a passport. A child born in France to foreign parents needs to apply for citizenship in his or her teens, and then prove continuous presence.
However, the point still stands. Birth on the territory opens the way to membership of the nation.
But events in Mayotte show how in modern times pressures of demographic change and mass migration are leading governments to question what had until recently been matters of consensus.
Mayotte is currently prey to a wave of civil disobedience born of local fear of being overwhelmed by outsiders.
Lying 70km (43.5 miles) from one of the poorest countries in Africa – the Comoros islands – Mayotte has a “small boat” problem that makes the UK’s, over the Channel from France, seem puny by comparison.
Hundreds of people arrive every week in boats from the Comoros, in addition to whom there are now increasing numbers of asylum seekers from the Great Lakes region of Central Africa.
In the island’s hospitals more than 10,000 babies are being born every year – the majority to mothers from the Comoros. Mayotte’s overall population is estimated at 300,000 – but only half of them bear French passports.
Since mid-January “citizen’s committees” have set up roadblocks around the island, demanding a crackdown on immigration and the crime they say comes with it. From all political shades in Mayotte comes the same cry: end the droit du sol.
“If not, we will be perpetually the prisoners of our geography,” says Estelle Youssouffa, a Mayotte MP from the independent LIOT bloc in the National Assembly.
“We will end up welcoming all the misery of the Comoros and of Africa – all so that people in Paris can parade their grand principles.”
“The right to security is also a fundamental right,” argues Ms Youssouffa. “The right to move around freely is a fundamental right. But we are deprived of these rights – because the violence is now so bad we can no longer live normally.”
The French interior minister says he is responding to the appeals of the Mahorais, as the people of Mayotte are known. He says that once the droit du sol has been abolished on the island, the lure will disappear.
Currently most demands for regularisation are from the Comoran families of babies who are born on Mayotte and therefore French. When the babies are no longer French, the argument goes, the people will stop coming.
No-one knows if that is true or not.
For the left, it is not citizenship per se that draws immigrants to Mayotte, but the comparatively wealthier standard of living. And they warn that, for all the government’s promises to the contrary, what happens first in Mayotte could all too easily be followed in France as a whole.
No-one knows if that is true either.
What is undeniable is that both the mainstream and hard right in French politics are now talking openly about ending the droit du sol in France proper as well.
For them it is exactly the kind of shock measure that the immigration crisis requires, as asylum requests reached a record 142,500 last year.
The Macron government needs the political right to get through any constitutional change on Mayotte. Might they make their support conditional on the reform being broadened to France as a whole?
Or might they contrive to block the constitutional change on the basis that for Mayotte alone it is too restrictive? And then at the next presidential elections ride – they hope – to power, promising a nationwide end to the droit du sol?
The world is changing. It is possible.
BY BBC NEWS