Hamida Maiga looks out over a green field ringed by white suburban houses and low-rise apartment blocks here, and imagines the spires of a mosque's minarets rising above it all.
"Our one condition is that it look like a mosque so that people, when they drive by, will know what it is," he says, standing with two other members of the town's new Muslim Federation, which hopes to build an Islamic center on the site.
That modest wish is a radical aspiration in a country where stone churches are the central architectural statement in almost all cities and towns, and Christianity so permeates the culture that, for most French, it is an assumed part of the national identity.
While people here have grudgingly accepted a growing Muslim presence in their midst, many still resent displays of religious and cultural symbols suggesting that the country's second largest and fastest growing religion is here to stay.
But as the country's first major wave of Muslim immigrants retire and their French-born children come of age, the largest Islamic community in Europe is pushing for the social and religious institutions that it believes are its due.
In so doing, they have pushed right up against the French tradition that dictates by law a strict separation of church and state and the celebration of secular values. It is a tussle that is going on in various degrees across Europe: this month, Germany's highest court ended a long legal battle there by ruling that an Afghan-born Muslim teacher could not be forbidden to wear a head scarf in school. But the ruling left a loophole that may allow individual German states to pass laws expressly forbidding head scarves in schools.
In France, Muslim leaders have called for paid days off on Islamic holidays and the appointment of Muslim chaplains in hospitals, prisons and the military. At least two French cities now cater to Muslim women with female-only hours at public swimming pools.
Building mosques is highest on the Muslim agenda, both because of a physical need and a desire to demonstrate that the religion has incontestably arrived.
"Islam is a religion that is rising and is very strong, and that causes fear," said Zeinoul Abidine Daffe, a Senegalese who, in his tweed jacket and glasses, looks like a college professor. Mr. Daffe and Mr. Maiga, a native of Mali, have both spent the better part of their adult lives in France.
For 20 years, they and most of France's five million Muslims made do with tiny prayer rooms — often in the basements of buildings. Cergy's Muslims worship in a town gymnasium put at their disposal once a week. There are already more than 1,500 mosques and Muslim prayer rooms in France, but only a handful have domes or minarets because local governments consider such identifying details unnecessarily ostentatious, even inflammatory.
Now, dozens of mosque projects are making slow progress through France's formidable bureaucracy, and at least 10 of the planned buildings will be architecturally recognizable as mosques, with domes or minarets or both.
The Cergy mosque, still at least two years from realization, has already excited passions and led one local opposition politician to warn that its minarets might rise higher than the town's church steeples. The comment won the town national attention: the conservative newspaper Le Figaro ran a cartoon of a priest and an imam cranking up the towers on their respective houses of worship, each trying to top the other.
In fact, there has been no decision yet on whether or not the mosque will have minarets, though the town's Muslim leaders clearly want them. Instead, opposition to the mosque has focused on technical details — that it will clog traffic in the neighborhood, for example.
"A big mosque can change the silhouette of a neighborhood and the character of a town," said Jean-Marie Chaussonnière, a white-haired Cergy lawyer who has emerged as the most vocal critic. "I'm afraid it will only invite extremists."
Mr. Chaussonnière argues that taxpayers' money shouldn't be spent to support the construction of a mosque.
"This isn't our patrimony," he said over lunch at a local Laotian restaurant. "I don't want to pay for women to wear burkas."
Cergy's Muslims failed for 20 years to win local government support for a mosque and had threatened to protest by holding Friday Prayer outside the town hall. Their luck changed when the current mayor, Dominique Lefèbvre, won the 2000 elections with a slim majority, the left's strongest mandate in the town's history.
He set about addressing the Muslim concerns, promising to place the religion on equal footing with Catholicism in Cergy.
The problem was that Cergy's Muslims lacked means to build a mosque on a par with the local churches. The town wanted to keep them from turning for help to Islamic associations abroad. (Many of Europe's new mosques have been built with money from the rich countries of the Persian Gulf, particularly Saudi Arabia.)
To counter the risk of external influence, an increasing number of towns across France are bending the laws that prevent government from subsidizing religious institutions. They are leasing land to Muslims at nominal cost and subsidizing Muslim cultural associations that, in turn, administer the construction and operation of local mosques.
Cergy is doing the same — albeit on condition that the town's Muslims unite under a single rubric, and sign a charter pledging allegiance to France's republican ideals.
But stiff opposition could yet spoil the Muslims' plans. A proposed mosque in Sartrouville, eight miles southeast of Cergy, touched off a heated campaign two years ago against the "Islamization" of the town. Muslims there ended up buying an existing building to house their mosque, which was quickly shut down by the town for safety violations. It remains closed today.