France has denied citizenship to a Moroccan woman who wears a burqa on the grounds that her "radical" practice of Islam is incompatible with basic French values such as equality of the sexes.

The case yesterday reopened the debate about Islam in France, and how the secular republic reconciles itself with the freedom of religion guaranteed by the French constitution.

The woman, known as Faiza M, is 32, married to a French national and lives east of Paris. She has lived in France since 2000, speaks good French and has three children born in France. Social services reports said she lived in "total submission" to her husband. Her application for French nationality was rejected in 2005 on the grounds of "insufficient assimilation" into France. She appealed, invoking the French constitutional right to religious freedom and saying that she had never sought to challenge the fundamental values of France. But last month the Council of State, France's highest administrative body, upheld the ruling.

"She has adopted a radical practice of her religion, incompatible with essential values of the French community, particularly the principle of equality of the sexes," it said.

"Is the burqa incompatible with French citizenship?" asked Le Monde, which broke the story. The paper said it was the first time the level of a person's personal religious practice had been used to rule on their capacity be to assimilated into France.

The legal expert who reported to the Council of State said the woman's interviews with social services revealed that "she lives almost as a recluse, isolated from French society".

The report said: "She has no idea about the secular state or the right to vote. She lives in total submission to her male relatives. She seems to find this normal and the idea of challenging it has never crossed her mind."

The woman had said she was not veiled when she lived in Morocco and had worn the burqa since arriving in France at the request of her husband. She said she wore it more from habit than conviction.

Daniele Lochak, a law professor not involved in the case, said it was bizarre to consider that excessive submission to men was a reason not to grant citizenship. "If you follow that to its logical conclusion, it means that women whose partners beat them are also not worthy of being French," he told Le Monde.

Jean-Pierre Dubois, head of France's Human Rights League, said he was "vigilant" and was seeking more information.

France is home to nearly 5 million Muslims, roughly half of whom are French citizens. Criteria taken into account for granting French citizenship includes "assimilation", which normally focuses on how well the candidate speaks French. In the past nationality was denied to Muslims who were known to have links with extremists or who had publicly advocated radicalism, but that was not the case of Faiza M.

The ruling comes weeks after a controversy prompted by a court annulment of the marriage of two Muslims because the husband said the wife was not a virgin as she had claimed to be.

France's ban on headscarves and other religious symbols in state schools in 2004 sparked a heated debate over freedom and equality within the secular republic. The French government adheres to the theory that all French citizens are equal before the republic, and religion or ethnic background are matters for the private sphere. In practice, rights groups say, society is plagued by discrimination.

The president, Nicolas Sarkozy, has stressed the importance of "integration" into French life. Part of his heightened controls on immigrants is a new law to make foreigners who want to join their families sit an exam on French language and values before leaving their countries.