PARIS (Reuters) - France's main conservative party edged closer to resolving a crisis on Sunday as an ally of one of the two men disputing its leadership called for a new vote to pick a leader.
A two-week-old row over who won a November 18 vote for the UMP's presidency has plunged the opposition party into disarray and self-absorption, leaving Socialist President Francois Hollande unchallenged to advance left-wing policies.
It has prompted former president Nicolas Sarkozy to warn the rivals that they must find a solution to the deadlock by Tuesday or he will disown both in public, according to French media.
But a solution appeared to draw nearer as former minister Luc Chatel, an ally of contested UMP chief Jean-Francois Cope, changed his stance and called for a new vote to keep the party together.
"We need to let the members' voice be heard," Chatel told weekly paper Journal du Dimanche. "Nothing is more important than the party's unity, everything must be done to save it."
The option of a new vote has been touted by former prime minister Francois Fillon, who says Cope's win is not valid due to fraud suspicions and because it was confirmed by a biased committee. Cope says Fillon is trying to circumvent party rules.
To break the deadlock, former president Nicolas Sarkozy suggested holding a referendum on whether to hold a new vote.
But that option was rejected by Cope, after Fillon formed a breakaway parliamentary group with dozens of supporters that could soon compete with the UMP for millions of euros in public funding.
Chatel's appeal piled pressure onto Cope to moderate his stance, as the Journal du Dimanche reported some of his allies were starting to seek ways to stop the party from splintering.
In an apparent sign of softening, Cope said he would call a referendum soon on whether to reform the party's rules and whether he should remain its president until after municipal elections in 2014 - effectively cutting his mandate short by a year.
"You have decided to elect me, and we need to respect this verdict," he told party members in Nancy in northeast France.
But Fillon's camp rejected his proposal, calling it "unacceptable" and saying it ignored calls for a rapid re-vote.
Fillon renewed his call for a new vote during a visit to a town north of Paris and said he was ready to meet with Cope's camp on Monday. Meanwhile, his lawyer told French media he was ready to sue for a new vote if necessary.
The crisis has dragged Sarkozy into the fray for the first time since he lost an election in May, despite his duty as a member of the Constitutional Council to stay out of politics.
Friends told French media Sarkozy had warned the rivals to reach a settlement by Tuesday or he would publicize his view that neither was fit to run the party - a condemnation that could scupper their chances of running for president in 2017.
Friends say Sarkozy still keeps close watch on politics and may be eyeing another presidential bid in 2017.
(Reporting by Nicholas Vinocur; editing by Andrew Roche)