Full-body swimwear including the burkini should not be worn in public pools in the city of Grenoble, France's top administrative court ruled on Tuesday, upholding an earlier order by a lower court.
Grenoble's city council had voted in favour of allowing the use of burkinis on 16 May, sparking howls of protest from conservative and far-right politicians who said the move would undermine France's principle of secularism in public life.
The body-covering swimwear - which leaves only the face, hands and feet exposed - is often worn by Muslim women who wish to preserve their modesty in accordance with their beliefs.
"The new rules of procedure for the municipal swimming pools of Grenoble affect (...) the proper functioning of the public service, and undermines the equal treatment of users so that the neutrality of public service is compromised," the Conseil d'Etat said in a statement.
In a statement after the ruling was published, Grenoble city council said: "The municipality regrets that the Conseil d'Etat attributes to it intentions it does not have". It said its main aim was to guarantee equal treatment for all users.
Advocates of the burkini argue that without it, some women would choose, or be pressured by family members, to stay away from public swimming pools.
Grenoble's move was challenged by the French government and a lower administrative court suspended the measure. Grenoble responded by taking its legal fight to the Conseil d'Etat.
After its ruling, Interior Minister Gerald Darmanin said Grenoble's act had been "definitively overruled", welcoming the court ruling as "excellent news" in a post on Twitter on Wednesday evening.
The ruling was the latest development in a long-running dispute that has set defenders of France's secular values against those arguing that a burkini ban constitutes discrimination.
The all-in-one swimsuit, used by some Muslim women to cover their bodies and hair while bathing, is a controversial issue in France where critics see it as a symbol of creeping Islamisation.
The governor of the Isere region in southeast France had asked the court to intervene to stop the rule change from coming into effect in June.
The new rule had been championed by Grenoble's mayor Eric Piolle, one of the country's highest-profile Green politicians who leads a broad left-wing coalition locally.
The rule changes the council had approved would have allowed all types of bathing suits, not just traditional swimming costumes for women and trunks for men. Women would also have been free to bathe topless if they chose to.
Legal battles
The judges delivered their ruling on Wednesday evening after hearing arguments earlier the same day.
In their judgement, they said that the council's rule change meant some people could invoke religious grounds for not respecting the usual dress code in council pools.
Attempts by several local mayors in the south of France to ban the burkini on Mediterranean beaches in the summer of 2016 kicked off the first firestorm around the bathing suit.
The rules, introduced after a string of terror attacks in France, were eventually struck down as discriminatory. Three years later, a group of women in Grenoble forced their way into a pool with burkinis, sparking a political row.
French sports brand Decathlon found itself at the centre of controversy and was in 2019 forced to back down from plans to sell a "sports hijab" enabling Muslim women to cover their hair while running.
The debate about the burkini comes as French Muslim women footballers are battling to overturn a ban on the wearing of religious symbols during competitive matches.
The French Football Federation currently prevents players from playing while wearing "ostentatious" religious symbols such as the Muslim hijab or the Jewish kippa.
A women's collective known as "les Hijabeuses" launched a legal challenge to the rules in November last year.
