Former vice president of the European Aeronautic Defence and Space Company (EADS) Jean-Louis Gergorin, management consultant Arthur Andersen Florian Bourges and journalist Denis Robert are also charged with conspiracy in fabricating the list.

A judicial source said the complex trial could last about a month.

Villepin will have to answer the questions from Sarkozy's lawyer.

'I will come out of it free and clear,' Villepin said before the trial began.

Both Villepin and Sarkozy belong to the same political camp.