Juppe prepared to replace Fillon - Juppe associate

Alain Juppe, current mayor of Bordeaux and member of the conservative Les Republicains political party, reacts after he delivered his speech to recognise his defeat in the second round for the French center-right presidential primary election in Paris. REUTERS/Charles Platiau

Former French prime minister Alain Juppe is ready to step in as a conservative presidential candidate if the beleaguered Francois Fillon pulls out, a member of Juppe's entourage said Friday.

Juppe, 71, "will not refuse if all the conditions are met -- Francois Fillon has to take the decision to pull out himself and the rightwing and centre camps... have to be united behind him", the source said.

This comes as the spokesman for embattled French conservative presidential candidate Francois Fillon announced Friday he is leaving the campaign, the latest in a growing list of defectors.

"I've decided to end my duties as Francois Fillon's spokesman," Thierry Solere said on his Twitter account.

Fillon, 62, came from behind to beat Juppe in the rightwing nominating contest in November and Juppe returned to the southwest city of Bordeaux where he is mayor. He has kept a low profile since.

Fillon this week revealed he is to be charged over allegations he paid his British-born wife hundreds of thousands of euros to work as his parliamentary assistant, even though little evidence can be found of the work she is supposed to have done.

Police raided the Fillons' Paris residence on Thursday and more rightwing supporters deserted him, adding to the pressure on him to step aside less than two months before the first round of voting.

Far-right leader Marine Le Pen is leading polling ahead of the first round on April 23 but surveys currently show she will be beaten in the decisive runoff on May 7 by either the rightwing candidate or centrist Emmanuel Macron.