Vanuatu's opposition National United Party has rejected plans to merge with the governing Vanuaaku Pati, and instead is aiming to topple the government in a motion of no confidence.
Last week the Prime Minister, Edward Natapei, expressed the hope that the NUP could be brought into an enlarged governing coalition.
But the NUP leader Willie Jimmy now says his party has the support of some Government back benchers and has appealed for others to join him.
Mr Jimmy says the present Government does not deliver.
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.
However Serge Vohor, the Deputy Prime Minister, and leader of the second party in the current coalition, the Union of Moderate Parties, says none of their MPs have defected, and that the government will complete its 4 year term.