In the latest development in the case of Dominique Strauss-Kahn, French Socialist Party luminary and former head of the international monetary fund, today’s New York Post reports in an “exclusive” that New York prosecutors are ready to drop all charges. An anonymous source “at the center of the investigation” is quoted as saying: “We all know this case is not sustainable.”

Note first that Rupert Murdoch’s Post is not the most reliable source in this. Its theory, which it has assiduously promoted over the last few days (despite an apparent lack of evidence), is that Strauss-Kahn’s accuser is actually a prostitute, who turned against him only after he failed to pay her. For this the Post is now being sued for libel.

There’s something odd in the spectacle of a right-wing tabloid leaping to the defence of a left-wing politician, and a French one at that, but misogyny tends to trump party politics. And the underlying message of the story, that the prosecution case is near collapse, seems highly plausible.

But that doesn’t mean DSK’s worries are over. He also faces a complaint of attempted rape back in France, filed by writer Tristane Banon on the basis of an incident back in 2002, after which she famously likened Strauss-Kahn to a “rutting chimpanzee”.

Strauss-Kahn’s partisans see all this as part of a political conspiracy — Banon apparently writes for a website linked to Nicolas Sarkozy’s UMP. But even in France, it’s hard for a left-wing party to be entirely dismissive about claims of sexual assault, or to ignore the fact that Strauss-Kahn’s image has been seriously tarnished.

Nominations for the Socialists’ endorsement for next year’s presidential election close in a week’s time (for a ballot on October 9); even if the move for Strauss-Kahn’s rehabilitation gathers steam, that’s much too soon for him to be a viable candidate. And while in theory the deadline could be extended, or the rules could be changed to enable the issue to be reopened, there’s no real likelihood of that happening.

Things have moved on in Strauss-Kahn’s absence; there are several serious candidates for the nomination, including party secretary Martine Aubry, her predecessor François Hollande, and 2007 candidate Ségolène Royal. The fact that two of the three leading candidates are women may or may not help the party to withstand suggestions that Strauss-Kahn’s attitudes to women are symptomatic of a deeper cultural problem.

Aubry, who now appears to be the front-runner, represents the more traditional grassroots side of the Socialist Party — more suspicious of capitalism and modernisation than the cosmopolitan DSK. That may be what the party’s activists are looking for, and opinion polls still show her (like Hollande and Royal, although the latter markedly less so) with a convincing lead when matched against Sarkozy.

But there’s little doubt that Aubry would be a less formidable campaigner than Strauss-Kahn, and it’s hard to believe the continuing confusion and speculation over the latter’s role are doing the Socialists any good. From Sarkozy’s point of view the case has led to the removal of his most dangerous rival, and if the removal turns out to be partial rather than complete, that might be better still.