Vanuatu's Parliamentary Speaker, George Wells, has ruled a motion for a vote of no confidence in the new Government is invalid.
Parliament was due to hold an extra-ordinary session this Friday to debate the motion.
But Mr Wells says the opposition had not followed parliamentary procedures correctly when they deposited the motion against Prime Minister Sato Kilman last Friday.
He says it was left at the office of the clerk of parliament rather than in his office, while he was away at his Luganville constituency.
Mr Wells also claims one of the 27 signatories has since withdrawn his support meaning the opposition lacks the simple majority of the 52 MPs to force an extra-ordinary sitting of parliament.