French Polynesia's Union For Democracy claims to have enough support to dislodge the Gaston Flosse-led government in a no-confidence vote in two days.
Mr Flosse has ignored calls for his resignation despite a pre-election statement that he would step down if his party failed to win a majority.
The Union For Democracy leader, Oscar Temaru, says Mr Flosse is a bad loser after the Tahiti by-election left the Tahoeraa Huiraatira Party two seats short of a majority.
Mr Temaru says the motion was lodged once the result was official.
"To go through the process we had to wait for the response from the French High Commissioner and we got that yesterday. I mean that the French Government is accepting the results of the last election so it is possible to set up this motion of no confidence."