Police have warned there will be a heavy presence in the capital Port Moresby and outside parliament ahead of the resumption this afternoon.
The vote comes amid growing calls for Mr O’Neill to step down over a long-running corruption case.
Parliament has been suspended since police shot and injured more than a dozen University of Papua New Guinea students on June 8 as they prepared to march on Parliament to call for Mr O’Neill to resign.
Yesterday flights in PNG were disrupted as commercial pilots added pressure on the prime minister.
Earlier this week past prime ministers Sir Michael Somare and Sir Mekere Morauta also called for Mr O’Neill to stand aside.
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Under the constitution, a no-confidence motion must be tabled and voted on seven days later, but the opposition says the government may try to hold a vote today.
“We expect the speaker of parliament, the honourable Zurenuoc, to announce the motion on the floor, to put it on parliamentary notice, then to adjourn for seven days, on which the members will be prepared to come next Friday to debate it, and vote on it, it’s a simple as that,” opposition leader Don Polye told a press conference.
“The 121 members of parliament have a duty and are obliged to look through the motion, to analyse the reasons there and think about it.”
Mr O’Neill has appealed to MPs and the public to support his government and accused Mr Polye of undermining the national interest.
“In an uncertain global environment, we must maintain the unwavering political stability, and sound economic management,” Mr O’Neill said in a statement.
“The Leader of the Opposition cares only about trying to score political points, without any regard for the consequences for the economy or for individual businesses.
“The one threat to the sound growth would be a lurch into political instability, especially between now and the national elections that are now only months away.”
On Tuesday, the Supreme Court ruled the suspension of parliament until August by acting speaker Aide Ganasi was unconstitutional.
PNG’s parliament cannot consider a no-confidence motion within 12 months of an election, which is due next July.
Judges warned they would consider criminal sanctions if the government obstructed debate on the motion.
PNG police and military yesterday pledged to support each other to maintain law and order in the capital during the sitting of parliament.
“I don’t want anyone to feel intimidated, that we’re hindering them or stopping them from going to parliament,” Police Commissioner Gari Baki said at a press conference.
