Papua New Guinea Prime Minister James Marape has one week to save his job, with parliament to consider a no-confidence motion in his leadership next week.
On Tuesday, MPs convened in Port Moresby at the Supreme Court's behest after it ruled lawmakers must consider a motion brought by deputy opposition leader James Nomane.
Speaker Job Pomat affirmed the court's ruling and set the debate for 10am on Tuesday next week.
Mr Nomane says PNG has not progressed under Mr Marape, prime minister since 2019.
"The question that all MPs must ask themselves before the vote (is) if PNG is better off since James Marape took office?", he said, as reported by PNG newspaper The National.
The notice names Sir Peter Ipatas, the long-serving governor of the Enga province and leader of the self-created People's Party, as the alternative prime minister.
Australian National University fellow Terence Wood, a veteran PNG analyst, said Mr Marape's fate was unclear.
"No one can tell you in advance in PNG what's going to happen," he told AAP.
"You will be sure that all sorts of feverish negotiations."
He said Mr Marape's ousting was a "possibility not a probability".
"It could happen but the most likely outcome is Marape holds on," he said.
Mr Pomat urged both sides in the debate to show patience and respect.
"We must respect the rule of law and our constitution and our parliament. Thank you," he told MPs.
