PARIS (Reuters) - An embattled Francois Fillon on Wednesday accused his presidential rival Emmanuel Macron of seducing French voters without offering real reform, fighting to push his way back into the race even as opinion polls show his credibility crumbling.

Francois Fillon, former French prime minister, member of the Republicans political party and 2017 presidential election candidate of the French centre-right, delivers his speech during a campaign rally in Pertuis, France, March 15, 2017. REUTERS/Charles Platiau

Once the frontrunner, Fillon’s troubled election campaign suffered another blow on Tuesday when magistrates put him under formal investigation on suspicion of misusing public funds.

He lags behind Macron, who served as economy minister under Socialist President Francois Hollande and is running as an independent challenger, and the far-right leader Marine Le Pen who wants to haul France out of the European Union.

Fillon denies the allegations he paid his wife hundreds of thousands of euros of public money for hardly any work and says he is the victim of a “political assassination”.

“I am innocent. The judicial system is being taken advantage of,” Fillon told Radio Classique. “I won’t be coming in third. I will be in the second round,” he said, accusing Macron of offering very little to change the country.

“Macron has been trying to seduce everybody. There are no structural reforms in it,” he said.

He said on Wednesday that he had gone back on a promise to stand down if he was placed under formal investigation because the system had “derailed.”

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While Fillon has managed to get his party, The Republicans, to rally behind him and continues to keep a core right-wing vote of about 20 percent, his image is suffering.

In a sign he faces a struggle to keep all allies on side, Jean-Baptiste Lemoyne, a lawmaker from The Republicans, said he would back Macron, telling Reuters he now believed it was “impossible” for Fillon to win.

LOSING CREDIBILITY

Revelations that Fillon’s children transferred back to him large amounts of taxpayers’ money that he also paid them, and news of a parliamentary inquiry into a 13,000 euro ($13,800) gift of two suits Fillon accepted in February, have piled yet more pressure on the former prime minister.

The scandal has distracted attention from his proposals to cut 500,000 public jobs and slash the government’s bloated costs.

At a rally in south-eastern France, an area of strong support for the far-right, he sought to put the focus back on his economic reform program. But he faced a rowdy crowd of people who whistled and chanted for him to go to prison.

An Elabe poll published on Wednesday showed that less than 20 percent of French people believe he is honest, down from about 30 percent at the end of January. Only 36 percent of people now think he has the qualities to lead the country.

Daily pollsters Opinionway and Ifop on Wednesday both showed him losing ground on the leaders, now 6 to 7 points behind Macron, who is in second place behind Le Pen. Both polls showed Macron defeating Le Pen comfortably in the second round.

Le Pen, who has strived for several years to detoxify her National Front party’s image, was in combative mood after the party earlier said it would expel a regional official following reports he had played down the Holocaust.

In a style reminiscent of U.S. President Donald Trump’s campaign rallies, she launched a blistering attack on her opponents and the media, while defending her anti-immigration, protectionist policies as the only way to “liberate” France from the shackles of Europe.

“The Left and Right have run out of steam,” she said. “You can smell the scent of victory. Victory is close.”