France's highest administrative court on Thursday ruled the government's ban on abayas – a shoulder-to-toe over-garment – in schools was legal.
A Muslim rights group had sought to overturn the ban on the robe worn by some Muslim women and girls on the grounds that it was discriminatory.
But the State Council, France's top court for complaints against government authorities, rejected the motion.
The government last month announced the ban on abayas, saying they broke the rules on secularism in education that have already seen Muslim headscarves banned.
The court agreed the abaya constituted a display of religious affiliation.
'Discriminatory'
The association Action for the Rights of Muslims (ADM) had argued that the ban was discriminatory and could incite hatred against Muslims, as well as racial profiling.
France's Council of the Muslim Faith (CFCM), established to represent Muslims before the government, warned that banning the abaya could create "an elevated risk of discrimination" and said it was considering putting its own complaint before the State Council.
The absence of "a clear definition of this garment creates vagueness and legal uncertainty", it said.
French schools sent dozens of girls home for refusing to remove their abayas on the first day of the school year on Monday.
Nearly 300 schoolgirls defied the ban, Education Minister Gabriel Attal said.
Most agreed to change garments but 67 refused and were sent home, he said.
