The debate has gripped France for weeks, with Socialists, feminists, and critics of radical Islam, all siding with several seaside town mayors to ban the burkini, or full body-swim suit.
The mayor of Cannes banned it from the city's beaches last week, citing security concerns, and saying it goes against France's principle of secularism.
He got the backing of the prime minister.
"It is the expression of a political project, a counter-society, based notably on the enslavement of women," Manuel Valls told newspaper Le Provence, to the dismay of some in his Socialist party, who fear new hysteria over Muslims and accusations of Islamophobia.
Rows over Muslim women’s clothing have dogged French politics for more than a decade – from the ban on headscarves in state schools to Nicolas Sarkozy’s outlawing of the niqab, or full-face veil, in all public spaces in 2011.
"We know very well the law forbids people covering up their faces, but here, these women aren't doing that!" Mohammed Henniche, secretary general of France's Union of Muslim Associations told RFI.
He argues the burkini-- a wet suit like combo that covers the torso, limbs and head-- is not an "ostentatious" expression of Islamic faith, which was the argument used to enforce the burka ban.
"Furthermore, these women are coming to swim with other French women and what do we do? We find a way of stigmatizing them and excluding them from the rest of society, I find that really, really shocking."
Challenging the ban
He's not the only one. A French anti-Islamophobia association, CCIF, has challenged several court decisions upholding the burkini ban, including in Cannes. So far, in vain.
The court asserts that a burkini may not be seen simply as an innocent religious symbol, but as a militant and proselytising form of radical Islam, which hits a raw nerve in France in the context of state emergency.
"We understand France's concern," Khalid Chaouki, an Italian MP told RFI.
"Muslims in Europe must do more than in the past to explain their opinion, their will to live together with European citizens, but at the same time we have to be careful not to discriminate European Muslims."
Die-hard feminists see it as a danger to the very idea of French society.
"It's a provocation," Linda Weil-Curteil, a lawyer and co-director of the international league of women's rights, told RFI.
"They are saying we are not like you and we don't want to be like you. Our women are dignified, whereas you [French women] are sluts, because you dress you know in short skirts, in bathing suits, you offer your bodies to the lust of men."
The burkini is seen as an overt criticism of the loose morals of French women, popularized by iconic figures such as Brigitte Bardot.
"But you see, we are an old society with traditions that have come a long way," insists Weil-Curteil. That tradition is founded on unity and togetherness, and inherent in her criticism is the fear of separation.
"If these women or the men, show off in a way that hurts French society they're putting themselves aside."
In a country that fought so hard for women's emancipation, overcoming modesty checks on beaches in the West to give rise to the bikini, covering up is seen as a step back.
"We must defend the freedom of women, including Muslim women," reckons Chaouki.
"The burkini gives thousands of women, and girls the possibility to swim with their sisters, friends, and neighbours," he says, refuting the archaic vision of an Islam that keeps Muslim women at home.
Even once the summer heat has died down, the sparks caused by the burkini row will linger. It’s added new fire to the anti-immigrant rhetoric of the Far right.
"France doesn’t enslave the body of women, France doesn’t cover up half of its population, on the fallacious assumption… that the other half fears temptation," Marine Le Pen said on Wednesday, in support of the burkini ban. Like Manuel Valls.
It may just be a political calculation, with presidential elections just around the corner. But it’s opened up a new front in France’s existential conflict, where the female body- uncovered - is seen as victory against an overbearing Islam.