The resource-rich Pacific nation, home to tribal groups speaking some 800 languages, now has two rivals claiming to be prime minister, two men acting as governor general and two opposing police chiefs.
Hours after Governor General Michael Ogio swore in veteran premier Sir Michael Somare's government on Wednesday, Somare's ousted rival Peter O'Neill suspended Ogio and replaced him with a new appointee who then swore him in.
Neither Somare nor O'Neill is backing down in what is the country's worst constitutional crisis since gaining independence in 1975.
Britain's Queen Elizabeth is head of state of PNG, a Commonwealth country, and the governor general is her representative. This means she is one of the few people with authority to break the deadlock.
"Her role only arises when an absolute majority of parliament votes to dismiss the governor general," Anne Twomey, director of the constitutional reform unit at the Sydney Law School, said.
But she added that it was complicated by the fact that it was not clear who controlled parliament.
"I think the (Buckingham) Palace will be trying to take the phone off the hook and hope the courts and politics sort it out before she has to make any decision about this," she told ABC television.
The unprecedented upheaval has left bureaucrats in PNG -- a nation described by Australian diplomats as a "totally dysfunctional blob", according to a memo released by Wikileaks -- unsure of who they were meant to be working for.
Paul Barker, from the Institute of National Affairs in Port Moresby, said church groups, a powerful force in PNG, and other civil society leaders were seeking a compromise to the escalating crisis.
"They are trying to get the two leaders to sit down together and consider the national interest," he told AFP.
"They want them to reconcile and work towards some sort of caretaker government that can take the country through to elections next year."
He said he had been told the O'Neill faction was willing to engage and compromise, but the Somare side was less enthusiastic.
So far, the nation's military has remained mostly silent. Defence force chief Brigadier General Francis Agwi said on Wednesday the army does not want a political role.
