Updated

French presidential candidate Francois Fillon was given preliminary charges Tuesday in an investigation of taxpayer-funded jobs his wife and children received but allegedly never performed.

The charges further damage the former prime minister's chances at winning the two-round April 23-May 7 presidential election in which he once was viewed as the leading contender.

Investigating judges filed the charges Tuesday, Celine Clement-Petremann of the national financial prosecutor's office said. It was a surprise move — Fillon had said the judges summoned him for Wednesday, but they apparently moved up the decision.

Fillon is accused of misusing public funds, receiving money from the misuse of public funds, complicity in misusing public funds and improper declaration of assets, among other charges, the prosecutor's office said.

Fillon has denied wrongdoing and vowed to continue his campaign.

While it is legal in France for politicians to hire family members for legitimate jobs, the case against Fillion hinges on whether parliamentary positions he gave to his wife, Penelope, and two of their five children were real or fictitious.

Fillon's family members insist they did the work for which they were generously paid.

Legally, Fillon's case is about to enter into a new phase. Politically, the conservative candidate intends to keep campaigning.

Fillon initially said he would quit the presidential race if he were charged. However, he later decided to maintain his candidacy, explaining he has the legitimate winner of the conservative primary and that his Republicans party had no plan B to replace him as the nominee.

The decision caused a deep rift within the party, prompting many to abandon his campaign.

"There is only one thing that exists in a democracy: it's the people's will. The French will choose", he said Monday in a news conference.

Once a front-runner of the presidential campaign, Fillon has seen his popularity drop following successive waves of revelations in French newspaper reports since January.

The allegations over the allegedly illusory jobs have been particularly damaging to his campaign because Fillon used to tout his reputation for probity.

"Those who don't respect the laws of the Republic should not be allowed to run. There's no point in talking about authority when one's not beyond reproach," he said while running for the conservative nomination.

Independent centrist candidate Emmanuel Macron has overtaken Fillion in pre-election polls, increasingly appearing as the new front-runner.

Another top contender also has caught the attention of judicial investigators. Far-right leader Marine Le Pen and some members of her National Front party are targeted in several ongoing investigations.

Last week, Le Pen refused to appear before judges in a case concerning her European parliamentary aides.

Polls show Le Pen is likely to reach the second round of the election.