French judges have formally charged Les Republicains presidential candidate Francois Fillon for embezzling public funds in an ongoing investigation into accusations that he paid his wife for government work she did not do. If Fillon continues his campaign for the Elysee, he will be the first major candidate on a French ballot with a pending trial.

It's unlikely Fillon will see trial before the two-round presidential elections that will name the next president on May 7. If elected, the French constitution would grant Fillon immunity since it does not allow the president to face trial while in office. Prosecutors would suspend the case until the end of his five-year mandate.

However, his wife Penelope Fillon, whom Fillon allegedly employed in the fake job at the center of the scandal, would not have the same protection. She goes before judges later this month and could face charges of hiding embezzled money.

But polls and analysts suggest Fillon won't even make it past the first round of voting. According to political researcher Romain Lachat, who studies electoral behavior, the charges will not change much for the rest of Fillon's campaign.

"The indictment is not a surprise. Everybody assumed this outcome would arrive," Lachat said. "The accusations won't go away and the damage will stay until the end of the campaign. It won't change the dynamic or his line of defense."

The scandal has been a gift to Front National candidate Marine Le Pen and self-proclaimed independent centrist candidate Emmanuel Macron, the 39-year-old leader of the movement "En Marche!" and outgoing President Francois Hollande's former economy minister. Fillon's corruption headlines boosted Macron from his third-place position in the polls and he has since been trading first and second place with Le Pen.

In the latest poll by the French Institute of Public Opinion (Ifop), Le Pen leads round one at 26.5 percent of the vote with Macron trailing her at 25 percent. Fillon is a full six points behind in third at 19 percent.

Only two progress to runoff

With the two dark horse candidates taking the lead, Lachat says voter opinion and support are more volatile than if it were two establishment candidates.

"Voting intentions are more likely to vary in coming weeks than they would in a traditional race," Lachat said. "Macron has a stronghold at the moment but his supporters don't seem to be most convinced of their choice, contrary to Marine Le Pen, who has a large base of supporters."

Le Pen faces her own legal troubles for similar accusations of misusing public funds to pay her personal bodyguard as a European Parliament assistant, but she has refused to meet judges.

Macron is also a satellite figure in an investigation into a case of favoritism. Business France, a unit within his former economy ministry, allegedly gave a large contract to an events company without a public call to tender.

Fillon's family 'affaire'

Fillon has continually denied any wrongdoing after the satirical weekly Le Canard Enchainé originally made accusations in January that Fillon paid his wife with taxpayers' money for a parliamentary assistant job for which there was little proof that she worked. Then it was revealed that he had also paid two of his children generous sums well above minimum wage as interns.

The candidate apologized and said that perhaps it wasn't the best decision, but that he had done nothing illegal and that it was the the system that must change. In the beginning, he offered to withdraw his candidacy if prosecutors opened a formal investigation. Shortly thereafter, when officials actually opened the case, he backpedaled on that statement.

Fillon has since made it clear on multiple occasions that no matter what happens he will see his campaign through until the bitter end.

The presidential hopeful has lost high-ranking staffers in the fallout, including a campaign director. He has faced calls to withdraw from the race to make way for an alternative candidate. But the most obvious choice, Alain Juppé, the runner-up in the primaries last fall, put rumors to rest that he would fight Fillon's losing battle as the candidate for Les Republicains.

Trial by media?

Fillon's relationship with the press has become increasingly contentious since the scandal broke. He has called the accusations and investigation a "political assassination."

He was originally scheduled to appear before judges on Wednesday, but requested to move up his convocation by a day in order to preempt and minimize a media frenzy.

"A troupe of 300 journalists isn't compatible with the vision of justice I have," Fillon's lawyer Antonin Levy told French television. "There is a form of media pressure that I wanted to cut short, that harms the presumption of innocence."

Former President Nicolas Sarkozy of the same right-wing party was also recently indicted on charges of illegal campaign financing. If Fillon is convicted, he will join other high-profile center-right officials to receive guilty verdicts for corruption, including Jacques Chirac and Alain Juppé. Those politicians only received suspended sentences.