Vanuatu's opposition has filed a constitutional application in the Supreme Court challenging a decision by the Speaker of parliament against their no confidence motion.
The Speaker, George Wells, had declared on Monday that the opposition's motion of no confidence against the prime minister, Sato Kilman was not in order.
The opposition had deposited the motion against Mr Kilman last Friday with the signatures of 27 MPs.
But Mr Wells said this week that it was not valid because one of the signatories had withdrawn.
He also claimed the opposition did not follow the correct procedure of depositing the motion when they submitted it to the office of the clerk instead of his office.
The opposition claims that a member can only withdraw his signature inside the chamber and not in the speaker's office.
The office of the Supreme Court has confirmed the opposition's application and court will sit this morning on the matter.