Papua New Guinea’s chief justice, Sir Salamo Injia, faces court today charged with sedition by a government that he and two colleagues have ruled illegal. The arrest of Sir Salamo and the impending arrest of his two Supreme Court colleagues follows their ruling, for a second time, that PNG’s ousted prime minister, Sir Michael Somare, be reinstated.

The court’s ruling incensed the de facto government of Peter O’Neill, in particular Deputy PM Belden Namah, who led police and soldiers in the judge’s arrest. How the subsequent charge of sedition against Sir Salamo is addressed in court today will have profound consequences for PNG and, to a considerable extent, how it engages with the wider world.

The sorry drama of what amounts to the death of PNG’s constitutional government began late last year when then prime minister Somare had an extended stay in Singapore for medical treatment. Peter O’Neill persuaded several Somare supporters to cross to him, thus giving him a majority in Parliament, then declaring Somare’s East Sepik seat vacant and himself as prime minister.

O’Neill chose to declare Somare’s seat vacant because, had Somare returned, he would have proven the move invalid and possibly persuaded enough members of Parliament to defeat a subsequent motion of no confidence.

Last December, the Supreme Court ruled that Somare’s ouster from his seat and as PM was illegal and that O’Neill’s subsequent claim to the prime ministership was invalid. However, the public service crossed to O’Neill, the Governor-General vacillated and then went to O’Neill and the army briefly split in a botched counter-coup, before also consolidating around O’Neill’s claim to rule.

In its new ruling this week, two of the five Supreme Court judges chose not to participate, also appearing to have accepted as de facto the claim to being prime minister by O’Neill. The remaining three, however, reaffirmed their earlier decision on the illegality of O’Neill’s prime ministership. Deputy PM Namah then told the judges to resign their posts or face arrest.

The arrest of Sir Salamo by Namah on a charge of treason is based on the judges’ alleged interference in the process of government. Assuming that the Supreme Court does have the constitutional right — and responsibility — to rule on constitutional matters, on the face of it, the charge does not make sense.

But the O’Neill government has now shown that it will only respect the constitution if its interpretation accords with the de facto government’s wishes. The notion of separation of powers between the executive and the judiciary, critical to a functioning democracy, is thus all but dead in PNG.

If the court today finds in favour of the O’Neill and Namah’s charge, what is left of the judicial system will be hopelessly compromised. If it finds against the charge, O’Neill and Namah will either have to resign, thus destroying their political credibility and perhaps also face charges or, more likely, ignore this judicial finding also.

Either way, PNG’s democratic process has been critically, perhaps fatally, wounded. If the country now manages to limp towards an election, already delayed, the question will be the extent to which there will be an opposition. With no viable opposition and no rule of law, there is now a possibility that PNG will slide into becoming what amounts to a one-party state.

The only saving grace in PNG is the fragmented character of its politics and the potential for organisational disintegration inside the O’Neill-Namah government. The options then are either greater political chaos or a narrower and tighter grip on political power by O’Neill and Namah.

Meanwhile, Australia is sitting by, wringing its diplomatic hands, hoping for a good outcome but, more so, not to create further alienation. PNG has already decided that its profoundly compromised approach to government and rule of law is at odds with Australia, and may now seek comfort with a benefactor such as China.