Nauru's former President, Marcus Stephen, has challenged the way the Speaker, Ludwig Scotty, adjourned Parliament on Friday.
Mr Scotty read a letter from President Sprent Dabwido detailing his wish to dissolve parliament.
This will take effect next Friday unless there is a successful resolution to vote the government out before then.
Mr Scotty was also highly critical of the behaviour of MPs and said the House was in a shambles and he was embarrassed.
He then adjourned the House indefinitely.
But Mr Stephen, who was dumped from Cabinet last month, says this move was unconstitutional because it denied MPs the opportunity to challenge the dissolution.
He says the outcome may have been the same but the Speaker was determining the matter rather than the elected members.
Mr Stephen has indicated there could be a challenge when the Supreme Court sits for the first time this year, next week.