PARIS
It’s the most chilling warning you can hear in France: Dominique Strauss-Kahn is out on the town, looking for a good time.
When Julien Dray, a prominent Socialist Party deputy, had a birthday party for himself Sunday night at a cocktail lounge, he didn’t bother to tell his V.I.P. guests that he had invited the most notorious man in France.

The randy economist — once considered the leading prospect to beat Nicolas Sarkozy before a swan dive from grace — could not resist popping up as a Socialist Party pooper on the eve of the election.

Strauss-Kahn has felt isolated for months, a political pariah fighting an “aggravated pimping” charge involving a global prostitution ring here and a civil suit by a Manhattan hotel maid charging a “violent and sadistic” sexual assault. A Bronx judge denied D.S.K.’s diplomatic immunity defense on Tuesday.
But a D.S.K. friend said the former presidential contender was lonely in this runoff week, so he ignored the bad optics. The birthday party bar is in the ancient Saint-Denis neighborhood that was so rife with prostitution, it helped inspire Sarkozy, as interior minister, to pass a law toughening penalties on soliciting. The bar itself had once been a sex shop. In tribute to the history of Rue du Sex, as the owner calls his street, he once dubbed his appetizers “foreplay” and desserts “orgasms.”
Party guests included aides to François Hollande, the Socialist candidate who rose when D.S.K. fell, and Ségolène Royal, the porcelain beauty who had four children with Hollande and bypassed him as the Socialist candidate in 2007 but lost to the right-wing Sarkozy.

When Royal, who came with her daughter, learned that D.S.K. was en route, she left, as she grandly put it, “in the name of women’s rights and respect due to women.”
Le Parisien published a cartoon with D.S.K. in a slinky dress popping out of a cake singing “Happy birthday, Mister President,” as Hollande grouses: “This is the icing on the cake.”

The untimely emergence of his disgraced former rival — christened “the ghost” by the French press — was an embarrassment for Hollande, who is on track to become the first Socialist president since his idol and old boss François Mitterrand was first elected in 1981. Editorialists dryly wondered why the Socialists were making one last push to re-elect the lagging Sarkozy.
Hollande, whose nicknames are the Living Marshmallow and Flanby, after the wobbly caramel pudding, felt pressured to be firm on speculation that D.S.K. would return as a minister in his cabinet. The fallen I.M.F. chief, who once thought he could save Europe’s economy, “no longer has a role in political life,” Hollande said.
It may be midnight in Paris for Sarko, but the fiery president is not going down to his calmer, less-colorful opponent without a fight.

Accused by Socialists and Communists of rhetoric fraught with fascist overtones on immigration and security, and slammed by an investigative Web site charging that Muammar el-Qaddafi offered Sarkozy a 2007 campaign contribution of 50 million euros, or about $66 million, Sarko threatened to file a complaint against the Web site and used D.S.K.’s reappearance to try to reclaim moral high ground. Strauss-Kahn “should have the decency to shut up,” Sarkozy told Le Parisien. “The fact that he dares to speak shows that he does not get it. I wish Mr. Hollande good luck with such support.”

While Hollande was offering what Sarah Palin would call a “hopey, changey thing,” D.S.K. was dominating the headlines. He gave an interview to Edward Jay Epstein in The Guardian connected to Epstein’s new e-book about the Sofitel case; D.S.K. was so suspicious that French intelligence had him under surveillance before the fateful stay at the Sofitel that he had his seven cellphones encrypted for a time. He charged that the drama there was “shaped by those with a political agenda” — Sarkozy allies — to derail his path to the Élysée Palace.

Le Figaro published the transcript of D.S.K.’s testimony to judges in Lille about the prostitution ring. He denied knowing that money was given to the young women who came to his “soirees libertine” at hotels in Washington, Paris, Lille and Belgium: the escorts were referred to in texts between D.S.K. and a friend as “equipment” and “pretty new things” to “test.”
He was pressed by a female judge about whether his entourage had put together a global “system” of sex parties to “satisfy your sexual needs,” assuming they would get favors in return from the possible president-to-be.

As the rest of Europe urgently argued about austerity, Strauss-Kahn patiently explained about debauchery. “You have to understand something,” he instructed. “Libertinism consists of having free and consensual sexual relations.” For free.
But, according to Le Figaro, a stripper-hooker named Jade testified that “I did not go and sleep with Dominique Strauss-Kahn simply for pleasure. First of all, he is old. He is stout.”
The 63-year-old insisted that the “pretty new things” were motivated merely by lust for him. And, if you believe that, I’ve got an Eiffel Tower I want to sell you.