Dominique Strauss-Kahn was hit with a fresh complaint of attempted rape in France on Tuesday, a new hurdle to any political comeback, even though U.S. sex assault charges against him may be lifted this month.

The New York Post cited an unnamed senior investigator as saying prosecutors would drop their charges at a court hearing in two weeks, or even earlier, due to doubts about the credibility of the alleged victim.

In Paris, however, French writer Tristane Banon filed a legal complaint alleging Strauss-Kahn tried to assault her in 2003, when she was 22, her lawyer David Koubbi told Reuters.

Banon, an author and journalist, gave a graphic account in a 2007 TV talk show of her allegation Strauss-Kahn tried to rape her during an interview in a Paris apartment. Tuesday was the first time she has taken legal action.

Her complaint will be examined by a judge who, as a matter of course, would question both Banon and Strauss-Kahn, sending investigators to the United States if necessary, before deciding to either place the Frenchman under investigation or dismiss the case.

In yet another twist to a saga that has captivated much of the world, the hotel maid who accused Strauss-Kahn in May of trying to rape her sued the New York Post and four of its journalists on Tuesday for reporting that she was a prostitute.

Signs that the U.S. charges are unraveling have set off a round of political sparring that threatens to poison the run-up to an April 2012 presidential election that Strauss-Kahn had been tipped to win for the left.

French left-wingers, furious their star candidate has been all but knocked out of the election race, dismissed the Banon complaint as more evidence that Strauss-Kahn's foes are determined to bring him down.

Strauss-Kahn's destiny has been snatched from him. All his friends are asking how it is possible that a man who is director of the IMF and a presidential candidate finds himself in prison a few days before he submits his candidacy, said Socialist deputy Jean-Christophe Cambadelis, a close ally of Strauss-Kahn.

This is clearly a conspiracy against the Socialist Party, he told LCI television.

Asked about Banon's allegation, her televised account of which had Strauss-Kahn's name bleeped out, Cambadelis said: This is manipulation by a young woman who wants to extort funds from Dominique through a rape complaint.

Koubbi told French M6 television that talk of a plot against Strauss-Kahn was nonsense.

Strauss-Kahn plans to bring a counter-claim against Banon, his lawyer said on Monday, a routine response in France when a legal complaint is filed against a party who denies misconduct.

STRAUSS-KAHN FUTURE UNCLEAR

The Banon case may fizzle out after a preliminary inquiry, unless the judge deems there is tangible evidence of an attempted sexual assault. Given the years that have lapsed since the alleged incident, there could be little aside witnesses' conflicting statements to hold up a court case.

Regardless of the outcome, opinion polls since the weekend suggest that more than half of French voters think Strauss-Kahn's political career is already over.

Francois Hollande, the left's new election frontrunner, was dragged into the imbroglio on Tuesday, when he was asked during a trip to the French Caribbean island of Martinique to respond to Banon's allegation that he had known about the 2003 incident and encouraged her at the time to press charges.

I really want to put a stop to this controversy, rumours and gossip, Hollande told reporters in Fort-de-France. This is all becoming quite unbearable.

A judge released Strauss-Kahn from house arrest on Friday, although charges of attempted rape remained in place, after prosecutors said the hotel maid changed details of her story.

We all know this case is not sustainable, The New York Post quoted its source as saying on Tuesday.

A spokeswoman for the district attorney's office in New York would not confirm that prosecutors plan to drop the charges, saying they were still investigating the case.

Meanwhile, the 32-year-old Guinean immigrant filed a suit in a court in the Bronx, accusing the Post of publishing defamatory articles between July 2-4. The Post was unavailable for comment.

Strauss-Kahn's abrupt reversals of fortune have angered many French, who viewed his parading before cameras, unshaven and handcuffed, in New York as a gross violation of his rights.

The Socialist Party, struggling to find a candidate who can match Strauss-Kahn's know-how and experience, has said it is very unlikely he could make a late bid for the October party primary, but it would not close the door if he did so.

Strauss-Kahn today is not a man who is hungry for power, Cambadelis said. He is in a period of healing, rehabilitation, rebuilding, he's a man who's been hurt.

(Additional reporting by Anthony Boadle in Washington and Dominique Bareto in Fort-de-France; Writing by Catherine Bremer; Editing by Louise Ireland)