BY EOIN BLACKWELL
AAP

A MASS PROTEST against the government of Papua New Guinea by union leaders in Port Moresby failed to materialise after police said they would not let it go ahead.

Businesses in the capital closed their doors this morning in preparation for the protest, after Trade Union Congress general secretary John Paska said affiliates would protest at the gates of Parliament House from 10am.

He had planned to hand prime minister Peter O'Neill a petition demanding the repeal of two laws aimed at reining in the Supreme Court and parliament's recent vote to suspend the elections by six months.

But by this afternoon fewer than 500 people gathered to hear speeches in a field near Parliament House, where mostly unarmed police cadets huddled in groups awaiting an angry march from some of the union's 70,000 members.

Student groups couldn't make it, they said, because they had exams.