The Vanuatu opposition leader, Edward Natapei, says he is hopeful a judge will force parliament to sit today to allow for a vote for a new primer minister.
The prime minister, Sato Kilman, who was to face a vote of no confidence, resigned yesterday.
The speaker then told parliament that a caretaker administration, led by Mr Kilman, would run the country until March the 29th when MPs will elect a new prime minister.
But Mr Natapei says he has filed a statement in court this morning to have the parliamentary session reconvened today, and is waiting for it to be served to the speaker and attorney general.
He says he hopes for a ruling today.
"Standing orders nine-three, in fact, requires that if there is a vacancy in the office of the prime minister, the parliament needs to immediately or as soon as possible, to re-elect a new prime minister. So as soon as possible, as far as we're concerned, was yesterday."
Edward Natapei says if the ordinary session is reconvened today, the opposition has the numbers to elect a new prime minister.