The three-judge panel's decision triggers the automatic removal of their former colleagues from the bench.
Exiled former president Nasheed and JP leader Gasim Ibrahim are under investigation for refusing to return to prison after their medical leave expired.
The Adhaalath Party and former president Gayoom's aides denied any agreement to back a JP-led coalition in September's presidential election.
The Maldives was thrashed by Indonesia in the UN Security Council vote.
The Prosecutor General's office declined to press charges against the three opposition lawmakers.
There are doubts a free and fair election can be held in the Maldives.
India's prime minister has yet to visit the Maldives, despite taking office in 2014.
The Maldives prisons authority spent millions unlawfully or accumulated it as a loss.
The Elections Commission has made public a list of eligible voters for September's presidential poll.
The Maldives was thrashed by Indonesia in the vote for a UN Security Council seat from the Asia-Pacific region.
The opposition appears divided in its quest to field a unity candidate.
Indonesia got more votes than the Maldives in the contested election for one Asia-Pacific seat by 144 to 46.
The head of the electoral body is a loyalist of President Abdulla Yameen.
Ambassadors are confident India will vote for the Maldives to get a seat on the UN Security Council, despite nosediving bilateral ties.
