The French Polynesian opposition Union For Democracy says it needs two more assembly members to join its ranks to oust the government of Gaston Tong Sang.
The opposition has lodged a motion of no confidence less than two weeks after Mr Tong Sang's eight-month-old coalition government lost the support of most of his party's assembly members.
An assembly sitting is to be called within two days for a vote in the 57-member assembly.
The Union For Democracy's Myron Mataoa says Mr Tong Sang can no longer govern as he can count on only about 20 percent of the assembly members.
"We are about 26 of us and we need three more. We have one that is for sure. Mr Michel Yip who has already stepped out of the government. And we need just two more to go for it."
The Union For Democracy, which lost power in a no-confidence vote last December, tabled a no-confidence motion earlier this year but failed to get a majority to support it.