Former French President Nicolas Sarkozy faces a historic trial over allegations of illegal campaign financing linked to Libya.

The National Financial Prosecutor's Office has demanded a seven-year prison sentence, a €300,000 fine, and five years of ineligibility for Sarkozy.

Prosecutors accuse him of orchestrating a "corruption pact" with Libyan dictator Muammar Gaddafi to fund his 2007 presidential campaign.

Sarkozy denies the charges, calling them baseless and politically motivated.

The trial has revealed a "dark chapter" of alleged corruption at the highest levels of the French state.

Sarkozy, already convicted in a separate case, vows to fight for his innocence as the court deliberates.