A candidate looking to lead France’s opposition UMP party has called for demonstrations against the Socialist government’s policies, including plans to legalise gay marriage. But far-right leader Marine Le Pen has threatened to steal the show. Marine Le Pen, the head of France’s far-right National Front (FN), has said her party would join anti-Socialist demonstrations proposed by the head of the centre-right opposition UMP party, dealing a significant blow to his credibility ahead of a leadership contest. Jean-François Copé has said that if he wins the battle for the party’s presidency against former Prime Minister François Fillon on November 18 – which polls say looks unlikely – he would launch street protests against Socialist policies that threaten the “pillars of society”. Chief among these supposed threats is a proposed law to legalise gay marriage and give greater parenting rights to same-sex couples, including adoption, which has drawn the anger of French conservative groups. In late October, pro-life group Alliance Vita, which says it has no religious or political affiliation, organised demonstrations in 75 towns and cities across France against the proposed law, under the banner “Un Maman et Un Papa” (one mummy, one daddy). Having the FN join UMP-sponsored protests would be an acute embarrassment for Copé, whose party is struggling to distance itself from a far-right movement that commands significant popularity – Le Pen won 18% of the vote in the first round of the 2012 presidential election – but inspires revulsion in many centrist voters. But as far as FN leader Marine Le Pen is concerned, Copé’s proposal is merely a desperate attempt at populism that proves that the traditional French right wing is dead in the water. She says her anti-Europe and anti-immigration party is ready to become France’s new mainstream conservative opposition to the Socialists. Asked during a debate on Christian TV station KTO if her party would join Copé’s proposed demonstrations, Le Pen replied: “Of course. When I have something to say it doesn’t bother me to demonstrate with people who may not necessarily share all my views.” Dismissing the UMP’s forthcoming leadership battle, which she said would make no difference to the future of the fractured party of former president Nicolas Sarkozy, Le Pen reserved her scorn for Copé, who she accused of shamelessly stealing her own party’s populist stance. “He has insulted, debased and rejected the FN and its voters, and now he has the gall to come onto the FN’s political territory and its ideology in a vain attempt to win an internal party election.” Le Pen said her party, if it came to power, would repeal any law on gay marriage, which she said would “undermine the very foundations of our civilisation and the structures that protect family life”. Proposals to give same-sex couples the right to adopt children, she added, were “far more serious an issue than gay marriage”. The gay marriage bill will be presented to the National Assembly on November 7, and is due to be voted on at the beginning of next year.