Paris (dpa) - The wife of embattled French conservative presidential candidate Francois Fillon was Tuesday placed under formal investigation in a probe centring around her job as his parliamentary aide, a judicial source said.Penelope Fillon is being investigating in relation to possible charges including complicity in the embezzlement of public funds, complicity in abuse of company property, and receiving the proceeds of those offences, the source told dpa.Fillon himself, who protests his innocence, was placed under formal investigation earlier this month.He has dropped to third place in the polls, after far-right candidate Marine Le Pen and centrist Emmanuel Macron, since satirical newspaper Le Canard Enchaine first alleged that his wife did not work for her taxpayer-funded salary.The candidate of the centre-right Les Republicains party has denounced what he calls a "political assassination" and accused socialist President Francois Hollande of leaking information about the investigation.Earlier on Tuesday, Macron, who has emerged as front-runner since the allegations about Fillon surfaced, promised that if elected he would govern with "new faces."Hollande‘s former economy minister, who last year formed a new political movement called En Marche! (Forward), said half his ministers would be women.He would choose a prime minister on the basis of competence and experience, and a significant number of ministers would come from civil society, he said."I will not recruit my government from the leaderships of political parties," he promised.Polls put Macron roughly neck and neck with National Front leader Le Pen for the first round of the election on April 23, but favour him to win comfortably against her in the decisive run-off vote on May 7.Macron derided suggestions that En Marche! could not win a majority in subsequent parliamentary elections scheduled for June.If Macron is elected president but another party wins a majority in the National Assembly, he would in practice have to accept the majority party‘s nominee for prime minister, massively restricting his ability to implement his manifesto."We are the only formation that is winning more supporters every day," the candidate said, adding that 14,000 would-be parliamentary candidates had submitted their CVs and his movement would nominate one for each of the assembly‘s 577 seats.Macron pointed to Fillon‘s judicial woes and the lacklustre support from leading Socialist Party figures for their candidate, left-wing dissident Benoit Hamon."We are not the ones who should be asked if they can form a majority," Macron said.