Gambia

(1) A person who alleges that—
(a) any Act of the National Assembly or anything done under the authority of an Act of the National Assembly; or
(b) any act or omission of any person or authority, is inconsistent with or is in contravention of a provision of this Constitution, may bring an action in a court of competent jurisdiction for a declaration to that effect.
… (Sec. 5)

(1) The Supreme Court shall have an exclusive original jurisdiction—
(a) for the interpretation or enforcement of any provision of this Constitution other than any provision of sections 18 to 33 or section 36(5) (which relate to fundamental rights and freedoms);
(b) on any question whether any law was made in excess of the powers conferred by this Constitution or any other law upon the National Assembly or any other person or authority;
(c) on any question as to whether or not any person was validly elected to the office of President or was validly elected to, or vacated his or her seat in, the National Assembly;
(d) on any question whether any official document should be produced, or its contents disclosed, in proceedings before a court where such production is resisted on the grounds that its production or the disclosure of its contents would be prejudicial to the security of the State or be injurious to the public interest.
(2) Where any question referred to in paragraphs (a), (b) or (d) of subsection (1) arises in any proceedings in any other court, that court shall stay its proceedings and refer the matter to the Supreme Court for its determination, and such other court shall give effect to any decision of the Supreme Court in the matter.
… (Sec. 127)