The president of French Polynesia's assembly, Philip Schyle, says it would untenable if the Tahoeraa Huiraatira Party leader, Gaston Flosse, became the vice-president.
In an interview with Tahitipresse, he said it would damage the government's image and the image of all French Polynesia.
His comment follows discussions in recent days that suggest the current vice president, Edouard Fritch, may relinquish his position to Mr Flosse and try to secure Mr Schyle's job.
Mr Schyle says he would be prepared to quit the ruling majority if it came to pass that Mr Flosse was made the vice-president.
The president, Gaston Tong Sang, says such a change is not on the agenda while conceding that his coalition deal gives the vice-presidency to the Tahoeraa .
The opposition has also spoken out against Mr Flosse's possible return to the executive, saying it would be a bad look in Paris given his involvement in various judicial affairs.
Mr Flosse claims to have done no wrong and appealed all his convictions.