LA VERRIERE, France – When Faiza Silmi applied for French citizenship, she worried that her French was not quite good enough or that her Moroccan upbringing would pose a problem.

"I would never have imagined that they would turn me down because of what I choose to wear," Ms. Silmi said, her hazel eyes looking out of the slit in her niqab, an Islamic veil that is among three flowing layers that cover her from head to toe.

But last month, France's highest administrative court upheld a decision to deny citizenship to the 32-year-old woman on the ground that her "radical" practice of Islam was incompatible with French values like equality of the sexes.

It was the first time that a French court had judged someone's capacity to be assimilated into France based on private religious practice.

The case illustrates the delicate balance between the tradition of secularism and the freedom of religion guaranteed under the French Constitution.

Four years ago, a law banned religious clothing in public schools. Earlier this year, a court in Lille annulled a marriage on the request of a Muslim husband whose wife had lied about being a virgin.

The ruling against Ms. Silmi has received almost unequivocal support across the political spectrum, including among many Muslims.

Fadela Amara, a practicing Muslim who is the minister for urban affairs, called Ms. Silmi's niqab "a prison."

"It is not a religious insignia but the insignia of a totalitarian political project that promotes inequality between the sexes and is totally lacking in democracy," Ms. Amara told the newspaper Le Parisien.

Ms. Silmi moved to France after marrying a French national of Moroccan descent. Their four children were born in France. She applied for French citizenship, she said, "because I wanted to have the same nationality as my husband and my children."

Katrin Bennhold,

New York Times