PARIS -- Frigide Barjot has made a career of mocking the establishment of France, dressing in fluorescent pink sweaters, playing in a band called the Dead Pompidous and hosting a philosophy soirée at which she handed out T-shirts with the logo, "Kierkegaard is my homeboy."
But Ms. Barjot, born Virginie Merle 50 years ago, has also rediscovered her religious roots, writing a book called "Confessions of a Trendy Catholic." And she has become one of the main actors and voices in France's fierce debate over gay marriage, adoption rights and state financing for procreation assistance. It is a debate as sincere and confused, in a way, as Ms. Barjot's own involvement.
Despite her love of mockery and her support for the rights of gay couples, she is strongly opposed to gay marriage, and especially to the part of a proposed law that would allow married gay couples to adopt children and be recognized as their parents. On Sunday, she will help lead a large demonstration called "La Manif Pour Tous," or a demonstration for everyone, a follow-up to an initial protest in November.
Legalizing gay marriage -- "marriage for all" -- was a campaign promise by President François Hollande, a Socialist, but it has proved tricky and divisive in France, which is a secular republic but remains an essentially Roman Catholic country where few go to church. He promised to enact it within a year of taking office last May, and his draft bill will go before Parliament for debate by the end of this month.
Same-sex marriages are now performed in about a dozen countries and at least 9 of the 50 states in America, while it is constitutionally banned in others. But gay marriage was not a big issue in the 2012 presidential campaign, and there are a number of cases about its legality before the Supreme Court.
In France, religious leaders have become deeply involved, arguing that the government should be cautious before redefining the institution of marriage and legal "parenthood." The chief rabbi of France, Gilles Bernheim, has cautioned about toying with the idea that gender has become "a social role that we choose for ourselves," instead of "a given element of nature that man has to accept."
Pope Benedict XVI cited Rabbi Bernheim in a Christmas address opposing gay marriage, saying that it was wrong for people "to deny their nature and decide it is not something previously given to them, but that they make themselves." He drew a parallel between those who deplore "the manipulation of nature" where "our environment is concerned," but sanction it as "man's fundamental choice where he himself is concerned."
The intervention of religious leaders in opposition, including Muslims, has caused something of an uproar, especially among supporters of the Socialist government. The minister in charge of education, Vincent Peillon, has even warned parochial schools against having debates in classrooms about the merits of gay marriage and adoption, citing a threat to French secularism, bringing charges of Catholic-bashing.
"To make a child, you need a man and a woman," Ms. Barjot said. For a gay couple to become the legal parents of a child "is totally contrary to reality," she said.
She is quite happy for gay couples to have official status and legal protections. "The problem is not homosexuality, but human filiation," she argues -- a child's need to have legal affiliation and access to its biological parents.
Mr. Hollande and his government say that they were elected on a clear platform and will pass the "marriage for all" law, and that the legislature, not the street, will decide.
A careful political tactician, however, Mr. Hollande has said he wants to keep separate from the marriage law the demand of some Socialist legislators that the government also legalize access to state-financed help for married lesbian couples seeking to bear children. On this issue, Mr. Hollande describes himself as not having strong views, which means that he does not favor the idea.
Former President Valéry Giscard d'Estaing, a conservative, spoke for the ambivalence of France when he said he supported giving gay couples the legal rights of heterosexual couples, but reserving the term "marriage" for heterosexuals. A name like "civil union" has been suggested by some; others think that a strengthening of the legal rights under current laws would be sufficient.
There exists a form of civil union called a pacte civil de solidarité, or PACS. When passed in 1999 it was intended for gay couples, but as a halfway house to marriage it has been used predominantly by heterosexuals. It could, some suggest, be extended to have the full rights of marriage.
The opposition center-right party, the Union for a Popular Movement, is divided about whether to attend the demonstration. Like Ms. Barjot, many in the party favor a national referendum on the issue, which is highly unlikely. Even Marine Le Pen and the far-right National Front are of two minds -- opposing the law but divided on whether to take part on Sunday, with Ms. Le Pen against participation but allowing members to do so.
Gay marriage "is a hot issue and defines identity for a lot of people," said Dominique Moïsi, a French political analyst. "In moral terms, there is a kind of precautionary principle for some -- let's not go too fast or too far or be too radical."
France remains a Latin country, he said, and "there is a sense that when the church says: 'Let's not go too quickly. This is fashionable now and trendy, but aren't we breaking a longstanding taboo that has meaning?' a lot of people agree."
As for children, he said, "there is a difference between the life you protect and the one you create." A gay couple adopting an abandoned child is fine, many think. "But to create life for them is maybe going a bit too far," he said.
Armand Laferrère has just written a book, "The Liberty of Men," about the politics of the Bible. He is a gay Protestant, and he has problems with the law. "The real issue is about what it is to be a parent, not about marriage," he said.
Most French people agree that gay couples should have legal rights, he said. "But what's at stake is that the law gives arbitrary power to the state to decide who is a parent and who is not," he said. "That is a deep problem for the identity of the child, which should not be for the state to decide." Helping to raise a child as a couple "is different than claiming legal parentage," he added.
Many Muslims also oppose the law. Camel Bechikh, 38, runs Fils de France, a Muslim group that affirms French identity and is participating in the demonstration. Like others, he fears the law will produce more "communitarianism," with special-interest demands that will undermine the unity of the French republic.
Nicolas Gougain, a spokesman for the Inter-LGBT, a federation of many gay groups, said the law was certain to pass; the question is its parameters. "We're ready to debate the content," he said, arguing that the debate over artificial insemination is outdated. "Homosexual parenting is already here," he said.
The importance of the law, he said, is that it "recognizes and protects all families." In two years, he said, "it's going to seem surreal that we had this whole debate."
Scott Sayare contributed reporting.
This article originally appeared in The New York Times.