The Papua New Guinea supreme court says it will set a timetable next week to hear cases relating to the legality of a law passed by parliament to legitimise dumping the Somare government.
The court has ruled that it will set out a timetable for hearings on Monday.
In December, the supreme court ruled Prime Minister Peter O'Neill and the majority of parliament had acted unconstitutionally when they dumped the nine-year-old government of Sir Michael Somare, as well as ending the political veteran's 43-year career in parliament.
Parliament reacted by passing retrospective legislation legitimising its decision, citing Sir Michael's extended absence between late March and early September 2011 for medical reasons.
Amid mounting political unrest, which culminated two weeks ago in a failed mutiny at the behest of the ousted Somare cabinet, the court ordered all parties before a three-man bench on Tuesday.