According to BFMTV, the judge asked Sarkozy several questions to which the former president refused to answer, explaining that if he answered the judge's questions, "the separation of powers would no longer exist."
"There is a principle which goes far beyond me, which is called the separation of powers. I am not accountable for the organization of my cabinet or for the way in which I exercised my mandate to a court, but to the French people," he said at the court.
He said his summon was "completely unconstitutional" and "totally disproportionate."
The trial involves the irregularity of the multi-million contracts concluded between the French presidential office Elysee and nine pollsters during Sarkozy's mandate (2007-2012). Under French laws, these deals were not supposed to be negotiated in private, thus not respecting transparency and competitive bidding.
All the five former aides of Sarkozy are charged with possible acts of favoritism and embezzlement of public funds.
His plane landed in Cape Verde because it needed to be refueled to take off again. However, he was arrested and placed under house arrest until he was finally put behind bars, all this arbitrarily and against his will.