Papua New Guinea

(1) Subject to this Constitution, the Supreme Court has original jurisdiction, to the exclusion of other courts, as to any question relating to the interpretation or application of any provision of a Constitutional Law.
(2) Subject to this Constitution, where any question relating to the interpretation or application of any provision of a Constitutional Law arises in any court or tribunal, other than the Supreme Court, the court or tribunal shall, unless the question is trivial, vexatious or irrelevant, refer the matter to the Supreme Court, and take whatever other action (including the adjournment of proceedings) is appropriate. (Sec. 18)

(1) Subject to Subsection (4), the Supreme Court shall, on application by an authority referred to in Subsection (3), give its opinion on any question relating to the interpretation or application of any provision of a Constitutional Law, including (but without limiting the generality of that expression)any question as to the validity of a law or proposed law.
…
(3) The following authorities only are entitled to make application under Subsection (1):-
(a) the Parliament; and
(b) the Head of State, acting with, and in accordance with, the advice of the National Executive Council; and
(c) the Law Officers of Papua New Guinea; and
(d) the Law Reform Commission; and
(e) the Ombudsman Commission; and
(ea) a Provincial Assembly or a Local-level Government; and
(eb) a provincial executive; and
(ec) a body established by a Constitutional Law or an Act of the Parliament specifically for the settlement of disputes between the National Government and Provincial Governments or Local-level Governments, or between Provincial Governments, or between Provincial Governments and Local-level Governments, or Local-level Governments; and
(f) the Speaker, in accordance with Section 137(3) (Acts of Indemnity).
(4) Subject to any Act of the Parliament, the Rules of Court of the Supreme Court may make provision in respect of matters relating to the jurisdiction of the Supreme Court under this section, and in particular as to-
(a) the form and contents of questions to be decided by the Court; and
(b) the provision of counsel adequate to enable full argument before the Court of any question; and
(c) cases and circumstances in which the Court may decline to give an opinion.
… (Sec. 19)