Reuters:

French Muslims have begun joining a mostly Catholic-led movement against same-sex marriage, widening opposition to the reform that the Socialist-led government is set to write into the law by June.

Fifty Muslim activists issued an open letter on Monday urging fellow Muslims to join a major Paris protest against the law on Sunday. That followed a similar appeal last Saturday by the influential Union of French Islamic Organisations (UOIF).

Leaders of almost all main faiths in France have spoken out against the law, but not called on their followers to march in Sunday's demonstration to avoid giving the opposition campaign an overly religious tone.

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We will protest on January 13 by joining a pluralist campaign to preserve the traditional framework of marriage," the Muslim activists' letter said. "We invite all French Muslims to turn out in large numbers."

The UOIF statement also urged Muslims to join the "March for All", the Paris protest against the reform the government has dubbed "Marriage for All".

"This bill, if it passes, will disrupt family and social structures and civil law dangerously and irreparably," it said.

The Muslim activist letter was signed by intellectuals, business leaders and leaders of several grassroots Muslim groups.