Papua New Guinea's top watchdog has asked the prime minister to call a session of parliament in March to comply with constitutional requirements.
The chief ombudsman, Ila Geno, says if Sir Michael Somare fails to comply he faces the prospect of being taken to court.
The National newspaper reports that there has been an exchange of letters between the two men arising from Sir Michael's decision in January to adjourn parliament until late June.
Mr Geno says the reasons given by Sir Michael for his position are not sound.
He says section 124 states the frequency with which parliament is to meet.
Observers say Sir Michael faces the possibility of a no confidence vote in his administration.