PARIS (Reuters) - French presidential candidate Francois Fillon accused President Francois Hollande on Thursday of being involved in what he alleges is a government plot to spread damaging media leaks about his affairs to destroy his chances of being elected.

FILE PHOTO: 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 at the Association of the Mayors of France (AMF) conference in Paris, France, March 22, 2017. REUTERS/Charles Platiau

The conservative Fillon, the campaign’s one-time front-runner whose poll ratings have plunged amid a financial scandal, stepped up his allegations that he is a victim of a plot by launching a direct attack on the Socialist president.

“You have newspapers today which receive documents 48 hours after they were seized in searches, for example in my office in the National Assembly. Who gives them these documents? The state services,” he said in an interview with France 2 television.

Asked if politicians or the justice system gave approval for this, Fillon said: “I will go much further. I blame the president of the republic.”

In response to Fillon’s latest allegations, the president’s office said Hollande “condemns with the greatest firmness the false allegations of Fillon.”

“The executive has never intervened in any judicial procedure and has always strictly respected the independence of the judiciary,” it said in a statement, adding that Fillon’s allegations brought “intolerable discord” to the campaign.

Fillon demanded an inquiry into allegations which he said are included in a soon-to-be-published book, by two journalists, that all judicial phone taps that interested Hollande were sent to the president’s office. “It is a state scandal,” he said.

Fillon said earlier this week that the aim of the alleged campaign of media leaks against him was to neutralize him as a force in France’s presidential election being held over two rounds in April and May.

Fillon, a 63-year-old former prime minister, seemed comfortably on course late last year to recover power for the center-right after five years of Socialist rule.

That was until media reports in late January sent his ratings tumbling by disclosing he had paid his wife Penelope and two children hundreds of thousands of euros of public funds for work they may not have carried out.

Fillon is now under formal investigation by magistrates on suspicion of embezzling public funds.

Fillon, who has repeatedly denied wrongdoing, said again on Thursday he would be proved innocent.

The fraud investigation into Fillon widened last week to include luxury suits he received as gifts.

Well-known lawyer Robert Bourgi gave Fillon made-to-measure suits worth 13,000 euros ($14,000) from exclusive Left Bank tailor Arnys in February.

Fillon said in the interview he had been wrong to accept the suits. He said he had returned three suits, but admitted he had already worn them.

“I was wrong to accept them. I see that shocked many people. I made an error of judgment. So I have returned these suits to the person who gave them to me,” he said.

Fillon said no one had ever previously questioned his integrity during 36 years of public life and said the image that was being painted of him had made him think of Pierre Beregovoy, a former French prime minister who committed suicide in 1993.

He said he “understood why you could be led to this extreme.”

Opinion polls now suggest Fillon will be eliminated in the first round of the presidential election on April 23 and that the May 7 run-off will be between independent centrist Emmanuel Macron and far-right leader Marine Le Pen.

Two members of France's Socialist government deserted their party's official contender for the presidency on Thursday and threw their support behind Macron, significantly bolstering the 39-year-old's bid for the Elysee palace. (GRAPHIC - Polls point to Macron win tmsnrt.rs/2jLwO20)

The biggest catch for Macron was the defection of Defence Minister Jean-Yves Le Drian, a Socialist Party grandee who has been a close ally and friend of Hollande for nearly 40 years.

In a sign of Macron’s growing popularity, the daily Ifop-Fiducial poll for the first time on Thursday showed Macron winning both the first round and the decisive run-off vote. A Harris Interactive survey showed the same outcome.