France's highest administrative court said on Thursday that the country's football federation is entitled to ban headscarves in competitions even though the measure can limit freedom of expression.

The Council of State issued its ruling after a group of headscarf-wearing football players called "Les Hijabeuses" -- the word hijab refers to the headscarf -- campaigned against the ban and launched legal action.

The ruling is likely to refuel the lingering debate on secularism -- still volatile more than a century after the 1905 law on separation of church and state that established it as a principle of the French Republic.

The French football federation bans players from wearing headscarves and other religious symbols in official matches, as well as at competitions it organises. It's not in line with the recommendations of football governing body FIFA, which authorises players to compete at international level with headscarves.

The French federation said the ruling gave it the opportunity to "reaffirm the republican and civic values that underpin football, and its total commitment to combating all forms of discrimination and promoting gender equality."

The Council of State said sports federations "may impose on their players an obligation to wear neutral clothing during sporting competitions and events, in order to guarantee the smooth running of matches and prevent clashes or confrontation. It considers that the ban imposed by the FFF is appropriate and proportionate."

Unusually, the court did not follow its public rapporteur's recommendations, who earlier this week said Article 1 of the federation's rules should be annulled. The article prohibits "the wearing of any sign or dress ostensibly manifesting a religious affiliation," and applies to matches and competitions organised.

It is unclear whether the ban would be implemented for next year's Paris Olympics.

The rapporteur had argued that religious symbols were already present in football, citing the example of players crossing themselves before entering the field.

The court recalled that federations are free to determine the rules for participation in their events, including rules on clothing and equipment.

"The rules of participation laid down by these federations may limit [the players'] freedom of expression of their opinions and convictions in order to guarantee the proper functioning of the public service," it said.

French Interior Minister Gerard Darmanin told RTL radio earlier this week he was opposed to the wearing of the hijab during sports competitions.

"You don't wear religious clothes when you play sports," he said. "When you play football, you don't need to know the religion of the person in front of you."

Right-wing senators vainly tried last year to introduce an amendment to a law on sports that would have extended the ban on headscarves to all sports competitions, arguing that neutrality was a requirement on the field of play, and that headscarves could put at risk the safety of athletes wearing it when they practice their discipline.

The amendment was rejected in the lower house of the Parliament after a fierce debate.

Lawmakers had previously approved a bill to strengthen oversight of mosques, schools and sports clubs in a bid to safeguard France from radical Islamists and to promote respect for French values -- one of President Emmanuel Macron's landmark projects.

With France bloodied by terror attacks, few disagreed that radicalisation was a danger. But critics also saw the law as a political ploy to lure the right wing to Macron's centrist party ahead of the presidential election that Macron won.