A motion of no-confidence against prime minister Joe Natuman is expected to be debated in Vanuatu's parliament today.
Notice of the motion, signed by 21 of the country's 52 MPs, was lodged with the parliamentary speaker last week.
The signatures include those of two MPs who have since been appointed government ministers and pledged their support for prime minister Natuman after he conducted a cabinet reshuffle.
The reshuffle saw the sacking of former prime minister Sato Kilman as foreign minister.