A court in French Polynesia has heard a case brought by the president Edouard Fritch who claims that his predecessor, Gaston Flosse, is ineligible to be a party leader because of his criminal conviction.
The hearing went ahead after it was deferred three times.
Last year, Flosse lost his civic rights for three years when he was also given a suspended four-year jail sentence and a large fine for corruption.
Mr Fritch argues that Flosse has also forfeited his rights to lead the Tahoeraa Huiraatira Party which two months ago moved to expel Mr Fritch, following months of acrimony.
Flosse's lawyer says there is no obstacle for Flosse to lead an association like a party, despite the conviction.
Mr Fritch also says Flosse has stayed in his leadership position despite a party rule which says a party member must be on the electoral roll.
A verdict is expected in two weeks.
Mr Fritch is poised to form his own party before the end of the year.