Tuesday's decision threw an unexpected wrench in a case that took years to make it to court and threatened to expose the ugly underbelly of French politics as the country gears up for next year's presidential race. He is the first former French leader to face trial since the World War II era.

The trial, which opened Monday, centers on Chirac's time as mayor of Paris from 1977 to 1995, before he became president. He enjoyed immunity from prosecution during his 12 years as head of state.