Claude Imbert, founder of the right-wing weekly Le Point, was condemned by the opposition Socialist party and by anti-racism groups after he told a news station that he regarded Islam as backward-looking and intolerant.
"Personally I am slightly Islamophobic and I don't mind saying it. I am not the only one in the country who thinks that Islam... is weakened by various archaisms - the way it demeans women, the way it wants to supplant the rule of law with the Quran," he said.
The Socialist party immediately issued a statement accusing him of promoting racism.
"How could a man of culture like Claude Imbert make such hate-filled, intolerant and xenophobic remarks about a religion?" demanded spokeswoman Annick Lepetit.
The Movement Against Racism and for Friendship between Peoples (MRAP) demanded Imbert stand down from the High Council for Integration, an official body that advises the government on immigration-related issues.
"Personally I am slightly Islamophobic and I don't mind saying it. I am not the only one in the country who thinks that Islam... is weakened by various archaisms - the way it demeans women, the way it wants to supplant the rule of law with the Quran"
Le Point editor
And Fouad Allaoui, the secretary general of the Union of French Islamic Organisations, told Aljazeera net that the French Muslim community was up in arms.
He said: "These comments are racist. He has taken advantage of an opportunity to stigmatise Islam and that is unacceptable in the Islamophobic climate which exists in France.
"In fact, these comments are against the law because they are pure incitement to racism."
He added: "If he had made statements like that against the Jewish community he would be condemned for anti-semitism.
"His remarks are based on nothing whatsoever - they are not true. He is mixing certain tradtional and cultural practices with the religion of Islam itself."
However, in Friday's edition of Le Point, Imbert counter-attacked, accusing his detractors of trying to stifle intellectual debate.
"It is for trying to draw a distinction between the critique of a religion and the execration of a race that the party of the politically pious is now trying me for witchcraft," Imbert wrote.
"All I have done is put forward the arguments of an agnostic against a revealed religion, reinforced by the reaction of a French citizen to the erosion of our secular tradition," he said.
In the editorial Imbert angrily denied the charge he was racist.
"These comments are racist. He has taken advantage of an opportunity to stigmatise Islam and that is unacceptable in the Islamophobic climate which exists in France"
Union of French Islamic Organisations
"For 30 years I have been defending the idea of immigration. Not because it is inevitable, but because I believe it is a positive benefit for a cocooned, aging society," he wrote.
But he repeated his view that Islam has been "ossified" for the last 700 years and is in need of a reformation similar to the process Christianity went through.
"It is clear that a reform-minded, modernist Islam is trying to escape from the Middle Ages. It is equally clear that more and more Muslims are developing patterns of free thought that loosen the grip of religion. But this whole process can only exist if there is open criticism of dogma and practice," he said.
Staff at Le Point were reported to be divided over their editor's views, and they were meeting on Friday to decide what position to take.
France is currently in the grip of a bitter debate over what allowances the state should make for the country's five million Muslims.
Many in France find Islamic religious obligations, such as women wearing headscarves, controversial in a secular country.
However, French Muslims argue that practising Muslims pose no danger to France's secular system and culture.
They say they are not asking for special privileges, but are only calling for their rights as French citizens.