Facts:
Executive Order No. 284 issued by President Corazon C. Aquino on July 25, 1987. The pertinent provisions of the assailed Executive Order are:
Sec. 1. Even if allowed by law or by the ordinary functions of his position, a member of the Cabinet, undersecretary or assistant secretary or other appointive officials of the Executive Department may, in addition to his primary position, hold not more than two positions in the government and government corporations and receive the corresponding compensation therefor; Provided, that this limitation shall not apply to ad hoc bodies or committees, or to boards, councils or bodies of which the President is the Chairman.
Sec. 2. If a member of the cabinet, undersecretary or assistant secretary or other appointive official of the Executive Department holds more positions than what is allowed in Section 1 hereof, they (sic) must relinquish the excess position in favor of the subordinate official who is next in rank, but in no case shall any official hold more than two positions other than his primary position.
Sec. 3. In order to fully protect the interest of the government in government-owned or controlled corporations, at least one-third (1/3) of the members of the boards of such corporation should either be a secretary, or undersecretary, or assistant secretary.
Petitioners maintain that this Executive Order which, in effect, allows members of the Cabinet, their undersecretaries and assistant secretaries to hold other government offices or positions in addition to their primary positions, albeit subject to the limitation therein imposed, runs counter to Section 13, Article VII of the 1987 Constitution, 2 which provides as follows:
Sec. 13. The President, Vice-President, the Members of the Cabinet, and their deputies or assistants shall not, unless otherwise provided in this Constitution, hold any other office or