limit adoption rights for same-sex couples – that have become a focus of the bitter second round run-off to win the right’s presidential nomination.

His more moderate centrist opponent, Alain Juppé, has accused Fillon of wanting to drag France back into the past, with “an extremely traditionalist vision, not to say slightly retrograde vision, of the role of women, the family and marriage”. He insisted Fillon must clarify his position on abortion.

Fillon, who abstained when parliament was voting on a 2014 law on the equality of men and women, has previously said that as a Catholic he is personally opposed to abortion but would not try to change the 1975 law that legalised it in France. Furious that the abortion issue was being dragged into the debate, he saidit was “grotesque and ridiculous” that he was being “billed as a medieval reactionary”.

Born in a traditionally Catholic region of western France, Fillon, 62, who with his Welsh wife raised his five children in a 12th-century chateau, has the support of hardline groups that oppose France’s same-sex marriage law. When the Socialist government introduced the legislation three years ago, it led to huge street protests, and the fractures in French society have not healed.

Facebook Twitter Pinterest Fillon with his Welsh wife, Penelope. Photograph: Xavier Laine/Getty Images

At his rally in Lyon on Tuesday night, leading figures from those street protests were present to applaud him. “I will put the family at the heart of all public politics,” Fillon promised to cheers. The family was “certainly not a place for