By Sophie Louet
PARIS (Reuters) - Former French president Nicolas Sarkozy's hopes of a political comeback got a boost on Tuesday after a fundraising campaign he spearheaded to avert a financial crisis for his conservative UMP party raised 8.3 million euros in less than a month.
The national drive to refill the UMP coffers - dubbed "Sarkothon" by the media - underscores Sarkozy's continued star appeal among centre-right voters despite his loss of the presidency to Socialist Francois Hollande in May 2012.
With the UMP's finances now largely repaired, Sarkozy can more easily prepare for a possible presidential bid in 2017.
For this, he will have to unite his fractured opposition party and present voters with a compelling alternative to Hollande, whose 14 months in office have been marred by a sluggish economy and rising unemployment.
French election auditors ruled this month that the UMP had overspent during Sarkozy's 2012 election campaign. As a penalty, they ordered it to repay the 11 million euros ($14.58 million) of state money it had been advanced.
Having raised most of this sum, the party is now negotiating a two-month extension to repay the full sum to French bank Societe Generale, UMP Treasurer Catherine Vautrin told RFI radio on Tuesday, averting the risk of default if the original July 31 deadline had not been met.
Vautrin said that 86,000 UMP voters out of the 300,000 on the books had donated to the party, while the party's lawmakers had been urged to contribute up to 2,000 euros each.
Sarkozy himself gave 7,500 euros, the maximum allowed under the law, she said.
Despite the flurry of support - and expectations that Sarkozy would send donors a thank you note - some politicians grumbled that the former president had not done more for the UMP party, which has been plagued by internal rivalries since Sarkozy left the public spotlight.
"Dare I say that he could have given maybe a bit more since he was the guarantor?" asked one UMP deputy, Bernard Debre, on iTele. "He should make an extra effort."
Sarkozy has remained largely out of sight since his defeat but in recent months has fanned speculation that he is mulling a re-election bid for 2017, telling a magazine in March that a duty to fix France's faltering economy might compel him to run.
The UMP's current president, Jean-Francois Cope, is a Sarkozy ally who has said he will give up any presidential ambitions for 2017 if his mentor decides to run again.
Arriving at a special UMP meeting on July 8 to address the sudden budget hole, Sarkozy was greeted like a rock star by hundreds of fans who shouted his name and pressed against barricades to shake his hand.
A CSA poll conducted in early July found that 67 percent of UMP voters named Sarkozy their top choice to run for president in 2017.
But any Sarkozy comeback would hinge on the outcome of a rash of legal cases involving people close to him, including allegations of illicit campaign financing and political rigging in an arbitration payout to a high-profile businessman.
($1 = 0.7545 euros)
(Writing By Alexandria Sage, editing by Gareth Jones)