Thousands demonstrated in Paris and other French cities on Sunday to protest corruption, taking aim specifically at presidential candidates Francois Fillon and Marine Le Pen, both accused of misusing public funds.

"To jail with the corrupt" and "Down with the privileged" read placards brandished on the Place de la Republique, the vast square in central Paris which has long hosted huge protests.

Conservative candidate Fillon has been mired in scandal since last month when it emerged that his wife netted at least $720,000 for a suspected fake job as a parliamentary assistant over a period spanning 15 years.

Two of Fillon's children were also put on the parliamentary payroll for brief periods.

Far-right leader Le Pen, for her part, was accused by the European Parliament of defrauding it of nearly $361,000 paid to two parliamentary aides.

"They have no right to lecture us on morality," said Patrice Roblet, a 66-year-old pensioner from the northern suburb of Val d'Oise.

In Toulouse, some 200 people banged pots and pans - a reference to a slang word for political scandals - and shouted "No to corruption".

Other protests were held in Lyon, Angers, Lille and elsewhere, with more planned for Feb 25 with elections looming in two months.

Fillon, who has denied the "fake jobs" allegations, said on Saturday that he would press ahead with his presidential bid even if investigators charge him over the affair.

Fillon, 62, had earlier pledged to drop out of the race if charged.

The claims have taken a heavy toll on his standings in the polls, with the latest Ipsos Sopra Steria survey of voter intentions putting him in third place in the first round of voting on April 23, with 18.5 percent.

Le Pen's standing has not suffered from the scandal, as she remains in first place for the first round, with 26 percent of voter intentions.

A woman holds a placard reading "Enough of the corrupted elected representatives who bring discredit on all the others" at a rally in Paris on Sunday.Lionel Bonaventure / Agence Francepresse