PARIS (Reuters) - France's leading Roman Catholic prelate said on Saturday a government plan to legalize same-sex marriage would profoundly affect the equilibrium of French society, calling it a reform for a few but not all citizens.
Speaking in the pilgrimage town of Lourdes, Paris Cardinal Andre Vingt-Trois urged Catholics to show their opposition to a planned marriage reform by writing and speaking to their elected officials or taking part in protest marches.
His call to action, announced at an annual plenary meeting of the country's Catholic bishops, came as President Francois Hollande's left-wing government prepared to present its draft bill on gay marriage in cabinet next Wednesday.
If the law passes, France - a traditionally Catholic society where churchgoers are now a single-digit minority - would become the 12th country in the world to allow same-sex marriage.
Opinion polls say voter support for same-sex matrimony has slipped several points to under 60 percent and to under 50 percent for gay adoption as the opposition has ratcheted up its campaign since last summer.
A BVA survey published by Le Parisien newspaper on Saturday said this was the first fall in support after a decade of rising acceptance for the two reforms. "Opinion trends on the subject are clearly on the retreat," it said.
French faith leaders - mostly Catholic, but also Jewish, Muslim, Protestant and Orthodox Christian - and conservative politicians have mobilized against the law, especially against its provision to allow gay couples to adopt children.
"The presidential and legislative elections (earlier this year) did not give them carte blanche, especially not for reforms that very profoundly affect the equilibrium of our society," said Vingt-Trois, calling the planned law "a fraud".
"It will not be 'marriage for all'," he said, citing the slogan of the pro-reform campaign, "it will be the marriage of a few imposed on all".
Green MP Denis Baupin, vice-speaker of the National Assembly, accused the cardinal of trying to prevent equal rights for all citizens. "Mr Vingt-Trois, respect the deputies, respect the citizens," he said in a statement.
Vingt-Trois did not openly call in his speech for street protests against the law, due to be debated in parliament in the first half of next year, but later told journalists his reference to "democratic means of expression" included them.
But he would not take to the streets himself. "My function is not to lead the political action, it's to awaken consciences and alert my fellow citizens when I think there is reason to do so," he said.
Lay Catholic groups organized protests in 75 cities around France last month and plan more in mid-November. The Church could organize a large demonstration but is wary of adopting too prominent a role in an emotional political debate.
Some conservative politicians have spoken out in favor of a large street protest in Paris and some mayors, the main officials who celebrate civil marriages, have said they would not preside over ceremonies for gay couples.
The cardinal said parliamentarians should be able to vote on the law according to their consciences, saying: "We appeal to their sense of the common good, which cannot be reduced to the sum of particular interests."
He said he had been invited to meet with deputies later this month to explain the Church's position.
Vingt-Trois accused the government of trying to rush through the marriage reform without a broad debate in French society about its implications, especially for children who would grow up without a clearly identified mother and father.
"Has it asked citizens if they agreed to no longer be the father or mother of their child, but only an undifferentiated 'parent A' or 'parent B'?" he asked, referring to a proposal to make references to parents gender-neutral on birth certificates.
Reacting to growing criticism, the government has scheduled longer parliamentary hearings on the bill than first planned but still aims to pass the reform by mid-2013.
France legalized gender-neutral civil unions in 1999 and almost as many are contracted every year as traditional marriages. But only four percent of those are among same-sex couples.
Additional reporting by Jean Decotte. Editing by Stephen Powell