The fiercely competitive world of French beauty pageants is not known for sparking philosophical debate between Catholic bishops and politicians, let alone a threatened uprising on an exotic ocean island. But the pre-Christmas contest for Miss France 2008 has caused a row over blasphemy, race and ancient colonial prejudice after it emerged that the winner once posed in a bikini as Jesus on a crucifix.

Miss World’s swimsuits and high-heels may be seen as passé in Britain, but across the channel the Miss France competition is a festive institution attracting about 10 million viewers in a three-hour prime time TV show.

This month a panel of sporting and showbiz celebrities, aided by a public vote, gave the crown to Valérie Bègue (22) a mixed race business student from the Indian Ocean island, Réunion. She returned to a hero’s welcome by the 800,000 inhabitants of the island off Madagascar, which, like Guadeloupe and Martinique, is considered as much part of France as the Côte d'Azur.

The first Réunion islander to be voted Miss France since 1978, Begue spoke of “diversity and tolerance” and celebrated the anniversary of the end of slavery.

But the mood soured when photographs taken three years ago were sold to a French magazine last week showing Bègue posing as Christ on a crucifix in a pink bikini. Other pictures showed her eating yogurt in a suggestive manner.

The head of France’s Miss World committee, Geneviève Fontenay — a haughty national institution known for her power suits and flamboyant hats — said Bègue should quit: “She’s in Réunion and she should stay there.”

But Réunion this weekend rose up in revolt. The public jammed radio phone-ins to accuse mainland France of racism and disdain towards islanders. Politicians demonstrated in the island’s capital. Public figures, including an MP from Nicolas Sarkozy’s ruling party, signed a letter demanding a public apology for the insult against Réunion islanders and all of France’s “overseas” citizens.

They said the row “reeked” of a “dark past” and bygone era in relations with France.

Bègue, pleading that the photos were private and a “mistake of youth”, refused to resign. Even Gilbert Aubry, bishop of the majority Catholic island, backed Bègue.

She had not offended him and he refused to allow the church to be used as an excuse to dethrone her. He said the pageant made contestants parade in bikinis and angel wings, also “a perversion of a religious symbol”.