PARIS - Members of former French President Nicolas Sarkozy’s opposition UMP party are warning that he is too much of a political liability for victory in 2017 as a funding scandal over his 2012 election campaign escalates.Sarkozy remains the top choice with most voters to be the conservative UMP’s presidential candidate, but even his allies are grumbling about his failure to comment on the affair and some are demanding the party consider other possible contenders. Since the leadership void caused by Sarkozy’s 2012 defeat at the hands of Socialist Francois Hollande, the UMP has been fractured by behind-the-scenes jockeying for position.‘Bygmalion - it’s a ticking time-bomb, when it really explodes for good, (Sarkozy) won’t escape the impact,’ one UMP member told Reuters, referring to the scandal named after the event organiser which admits it wrote fake campaign invoices. Sarkozy’s camp says he was unaware of any wrongdoing. This week the former deputy director of Sarkozy’s campaign, Jerome Lavrilleux, said four UMP members besides himself had agreed to use false accounting to cover rising campaign expenses that had surpassed a legal limit.Sarkozy was not among those. But Lavrilleux’s accusations came as investigative website Mediapart reported that the fake invoices totalled 17 million euros ($23 million), more even than the 11 million which Bygmalion has acknowledged. ‘It’s certainly possible that Nicolas Sarkozy wasn’t aware of the misbehaviour within his campaign,’ UMP lawmaker Herve Mariton told France Info radio on Thursday.‘But it’s just that he’s the candidate, and when you’re the boss, you’re responsible.’ Others have gone further, such as National Assembly member Bernard Debre, a backer of ex-prime minister Francois Fillon who is seen as a possible UMP presidential candidate in 2017, along with Alain Juppe, Sarkozy’s foreign minister. Debre told Radio Classique that the scandal plays right into the hands of a resurgent far-right National Front.‘We have to cut the dead branches,’ Debre said of his party. Two UMP deputies filed a lawsuit on Wednesday on behalf of ‘disgusted’ party activists against ‘persons unknown’ in the affair - a common formulation under French law for individuals who want to voice opposition. ‘How can you prepare a campaign in 2017 with such suspicion, such a degraded atmosphere, where everyone suspects everyone?’ asked Etienne Blanc, one of those deputies.Even if the police investigation finds that Sarkozy had no knowledge of the fake invoicing, five other judicial investigations either directly or indirectly implicate the ex-president, who lost his legal immunity after leaving office. Among other cases, magistrates are examining if the government paid a hefty settlement in 2008 to a French businessman with ties to Sarkozy; if France’s richest woman illicitly helped fund Sarkozy’s 2007 campaign; and if France paid kickbacks to Pakistan linked to submarine sales in the 1990s when Sarkozy was budget minister.Sarkozy has said he is innocent of wrongdoing in each case. ‘(Sarkozy) has an excellent lawyer, but there is always the risk that he doesn’t bring it all under control and that he’s indicted six months before the presidential election in 2017,’ said political scientist Thomas Guenole.