Vanuatu's week-old government faces a debate on a motion of no confidence on Friday.
The Daily Post reports that two government MPs have defected to Opposition Leader Maxime Carlot Korman's camp.
It says Vanuatu parliamentary officials have confirmed the petition for the motion of no confidence signed by 27 MPs complies with Parliament's procedures.
It means Parliament may meet in an extraordinary session if so requested by a majority of its members.
The two government MPs who signed the motion are believed to be Tanna MP Judah Isaac and former Health Minister Morkin Steven Iatika.
Mr Korman had warned Prime Minister Edward Natapei before he appointed his Cabinet that his coalition was fragile.
He lodged a motion of no confidence four days after the formation of the Natapei Government.