Members of French Polynesia's presidential intervention group, the GIP, have blocked access to the port of Papeete this morning in defiance of the president, Oscar Temaru.
The action follows Mr Temaru's televised address last night in which he vowed not to give into blackmail and to retain the GIP's new boss, Robert Maker.
A core group of the GIP has rejected Mr Maker's appointment to remain loyal to Leonard Puputauki who, Mr Temaru says, remains sacked pending legal action.
The stand-off has created a run on petrol in Tahiti for fear that the blockade may be protracted.
A member of the territorial assembly, Sabrina Birk, says the blockade is the result of the election loss of Gaston Flosse.
"Here we are a month and a half after and they are still not accepting that they have lost and now they are doing this. In a way they want a revolution, they want to provoke us. And what is really bad is that the French state, the high commissioner, is not interfering in this and is letting the situation degenerate."
Mr Flosse's party says it is not behind the blockade, but two weeks ago it described Mr Puputauki's sacking as a the start of a witchhunt.