PARIS - For Jacques Chirac, the legal clock is ticking: At midnight Saturday, the former French leader officially loses his presidential immunity, and could face investigators' questions -- or worse.

Judges could come knocking over at least five cases involving suspected corruption and alleged financial misdeeds, most dating to Chirac's time as Paris mayor from 1977 to 1995 -- the year he became president.

It's unlikely that Chirac, 74, would ever go to jail, but the cases loom as a humiliating coda to his four-decade political career. Since the Fifth Republic was founded in 1958, a former head of state has never been required to answer allegations of wrongdoing from earlier in his career.

"It will embarrass everybody. The current government isn't going to be thrilled, I'm not sure the opposition will either," said Yves Baudelot, a lawyer for the City of Paris in its efforts to recoup money lost to corruption scandals. "Whether you like it or not, it undermines the function of the president."

Chirac's lawyer, Jean Veil, said Thursday he has not received any summons for the former president to appear before judges, and declined further comment. A Chirac spokeswoman also declined to comment.

Dozens of people have gone on trial in the cases. Some involved kickbacks to help fund Chirac's Rally for the Republic party, since dissolved and replaced by the governing conservative Union for a Popular Movement.

Chirac is said to be concerned about the cases, and has been preparing a defense with advisers, sources familiar with the cases say. His memory of long-past affairs is likely to be put to the test if he is called.

Paparazzi plan to stake out Chirac's Paris apartment -- lent to him by the family of longtime friend Rafik Hariri, the assassinated former Lebanese prime minister -- to see if judges visit or to tail Chirac whenever he leaves.

Judges have long sought Chirac's answers in many legal probes, but were blocked from summoning -- much less prosecuting -- him during his 12 years as president, because of constitutionally guaranteed immunity for a head of state.

The most threatening case centers on suspicions that Chirac had a role in a so-called "fake jobs" party financing scandal in which operatives from his Rally for the Republic party were illegally on the Paris city payroll. The equivalent of millions of dollars in salaries and fees were doled out.

An investigation headed by Judge Alain Philibeaux in Nanterre, west of Paris, turned up a 1993 letter in which Chirac requested a raise for a secretary who was paid by City Hall -- but who actually worked at party headquarters.

The dossier landed a conviction in 2004 for former Prime Minister Alain Juppe, a top Chirac ally who was former financial director at City Hall. Juppe received a 14-month suspended prison sentence and yearlong ban from holding political office.

Chirac also could be called in the "Paris city representative" affair, an offshoot of the fake jobs scheme involving allegations that paid advisory posts were created at City Hall, but no work was ever done in them. Juppe answered an investigator's questions in that affair last month, raising suspicions that the former president soon could follow.

French media have been abuzz this week after the investigative satirical weekly Le Canard Enchaine said Chirac could be called to answer questions as early as Monday in the "Clearstream" case, a smear scandal that erupted during his presidency that centers on damaging -- but false -- allegations that Nicolas Sarkozy, now president, had secret bank accounts.

Another is the so-called "Euralair" file over a now-defunct airline whose founder is a close Chirac friend. It centers upon whether free flights allegedly provided to some beneficiaries -- including Chirac's wife, Bernadette, and possibly Chirac himself -- amounted to misappropriation of funds.

The fifth and final case involves allegations of favoritism and misappropriation of public money at City Hall's printing company, which had the equivalent of tens of thousands of dollars in losses when it was liquidated after Chirac's term as mayor.

As a former president, Chirac is guaranteed a seat on the Constitutional Council, a crucial body that judges the constitutionality of proposed laws. But it might be unseemly if he has legal troubles hanging over his own head.

Chirac left office May 16 with an undistinguished domestic record despite lofty promises, and will be perhaps best remembered for his popular opposition to the U.S.-led Iraq war.