Vanuatu's sacked finance minister, Willie Jimmy, has signed the opposition's motion of no confidence in the new prime minister Moana Carcasses's government.
Mr Jimmy was dismissed last week amid reports he was in contact with the opposition, which is led by a former prime minister, Sato Kilman.
Mr Jimmy's move comes despite him taking legal action against Mr Kilman, whom he accused of having been ineligible to stand in last year's election because he had failed to clear a debt to the state in time for the polls.
An opposition MP, Iatika Steven, says the motion has been signed by 26 MPs, but a Government Public Relations Officer, Letty Kaltonga, has denied this, saying the government is intact.
The motion is expected to be lodged in parliament before the end of the week, with the Daily Post newspaper suggesting it has the support of only 16.