Vanuatu's opposition National United Party has pulled out of a planned merger with the governing Vanuaaku Pati and instead is bringing a motion of no confidence in the government.
The NUP leader, Willie Jimmy, says they had no choice but to pull out of the merger after the government rejected a proposed cabinet reshuffle.
He says the current coalition cannot deliver and the country's economic state is worsening.
"Also, we believe there are internal issues that the government has mishandled, like police issues, the VMF, the VCMB, the marketing board, all this should not get out of hand. It's just a matter of weak ministers not deciding the right way of going about it."
Willie Jimmy says he has the support of a number of Government backbenchers.
Meanwhile, Maxime Carlot Korman, the leader of another opposition party, the Republicans, says a new coalition would lift the minimum wage, and drop the controversial debit tax.
But the deputy prime minister, Serge Vohor, who is the leader of the second party in the current coalition, the Union of Moderate Parties, says none of their MPs has defected, and that the government will complete its 4-year term.