The Nauru Government says the Supreme Court has unequivocally ruled in its favour, overturning attempts by the Opposition to amend the country's Citizenship Act.
Those amendments would have made two senior ministers ineligible to sit in Parliament.
The Speaker, Opposition MP David Adeang, had controversially held a meeting on Easter Saturday night, which was not attended by Government MPs and where the dual nationality provisions of the Act were removed.
The Government sought a legal review but Mr Adeang argued he had a quorum and that the courts had no jurisdiction over Parliament.
The Nauru Foreign and Finance Minister, Dr Kieren Keke, says the Chief Justice, dismissed the claims.
"It is quite landmark decision in that the Supreme Court has reinforced that no person and no institution, even Parliament with all its privileges and immunities, that its not even above the law, and must comply with the Constitution."
Dr Keke also says Mr Adeang's claims he had a quorum have been rejected.