A court will rule next month on an attempt by France's former justice minister, Rachida Dati, to have a millionaire hotel and casino owner recognised as her child's father.
Ms Dati, the former president Nicolas Sarkozy's protégé and one of France's most successful politicians of Maghrebin origin, says her three-year-old daughter, Zohra, is the result of an affair with Dominique Desseigne.
In the latest departure from restraint on the private lives of public figures, huge publicity has been given to claims on Mr Desseigne's behalf that she had seven other lovers around the time he allegedly made her pregnant.
The legal team acting for the 68-year-old chairman and chief executive of the Lucien Barriere group claims she had relationships with a former attorney general of Qatar, a Spanish prime minister, a French government minister, a company chairman, one of Mr Sarkozy's brothers and a television presenter.
For those familiar with French journalistic practice, there was surprise that the allegations should have surfaced in the weekend magazine of Le Monde, a left-of-centre newspaper with a reputation for combative journalism but not sensationalism or intrusiveness.
The portrayal of Ms Dati as a woman who befriended many men, several of them intimately, follows a relentless stream of information about the private life of Valerie Trierweiler, who as partner of the president, François Hollande, is France's "first lady".
Ms Trierweiler's life has been subject of intense scrutiny since confirmation two years ago that she had taken the place in Mr Hollande's life of Ségolène Royal, the beaten presidential candidate in 2007 and the mother of his four children.
A journalist who has insisted on combining Elysée duties with her career, Ms Trierweiler is suing Christophe Jakubyszyn and Alix Bouilhaguet, the authors of one recent book, La Frondeuse (The Rebel). It claimed she was having affairs with both Mr Hollande and Patrick Devedjian, a minister in Nicolas Sarkozy's government, when still married to her second husband. Mr Devedjian is also taking legal action.
Rumours about the supposed sexual exploits of rich or powerful individuals in France are hardly new. The difference in recent years is that they are no longer discussed exclusively by well-connected Parisians.
The press, once cautious and respectful, has increasingly challenged the strict privacy laws. The financial consequences are not sufficient to diminish the taste for disclosure.
Until 1994, the parallel life of the last French socialist president, François Mitterrand, who had a mistress and daughter along with a conventional family image, was an open secret in political and media circles. It remained unreported until the dying months of the presidency.
Mr Desseinge, who cannot be obliged under French law to take a paternity test, admits to having a brief "fling" with Ms Dati.
He says the relationship ended in early 2008 before she became pregnant and after he had made it clear he did not share her wish that they should have a child together. Mr Desseigne's lawyer, Michèle Cahen, famous for having acted in many divorce cases involving public figures, told Le Figaro newspaper her client had "legitimate reasons for contesting and opposing her demand (that he should undergo genetic tests)".
Ms Dati, 46, hopes the court will rule, as it has the right to do, that his refusal amounts to an admission. The court proceedings are not open to the public but her position is reported in France to be that her romantic relationship at the relevant time was "exclusively" with Mr Desseigne.
Le Monde quoted friends of Mr Desseigne as suggesting the politician sent him letters saying she would settle the case out of court in return for a pay-off.
Unlike Mr Hollande and the late Mr Mitterrand, Ms Dati is a figure of the centre-right.
She was born in Burgundy, one of 11 children of North African immigrants. Her father, a bricklayer, was Moroccan, her mother Algerian. A bright student, she pursued economic and business management courses, working as an accountant and qualifying as a magistrate and legal auditor.
From 2002, she was politically close to Mr Sarkozy. She was his official spokeswoman during his successful 2007 presidential campaign. After a tempestuous spell as his justice minister, during which she fell out with the legal profession over reforms of court procedures, she entered the European parliament.
She is the conservative Union for a Popular Movement (UMP) mayor of Paris's smart seventh district and has ambitions to become mayor of the city.
A court in Versailles, west of Paris, will deliver judgment in the paternity case on December 4.
Ms Dati has declined to comment beyond a robust denunciation on intrusive reporting quoted by the news magazine Nouvel Observateur: "Private life is private life. I want above all to avoid interference in my life as a mother. I have been strongly attacked in books with lots of gossip and slander written by so-called journalists. For me, they are not journalists but thugs. I think it's shameful."
Writing in the same magazine, the political commentator Bruno Roger-Petit said coverage of the dispute between Mr Desseigne and Ms Dati owed more to "voyeurism than information".
Defending a 1881 law prohibiting the reporting of family proceedings, he wrote: "There is no shame in being a journalist and to respect the law on freedom of the press, in terms of what it allows - when it comes to respecting privacy and dignity and what it does not."