Section 4. Postponement, Failure of Election and Special Elections. - The postponement, declaration of failure of election and the calling of special elections as provided in Sections 5, 6 and 7 of the Omnibus Election Code shall be decided by the Commission sitting en banc by a majority vote of its members. The causes for the declaration of a failure of election may occur before or after the casting of votes or on the day of the election.
In case a permanent vacancy shall occur in the Senate or House of Representatives at least one (1) year before the expiration of the term, the Commission shall call and hold a special election to fill the vacancy not earlier than sixty (60) days nor longer than ninety (90) days after the occurrence of the vacancy. However, in case of such vacancy in the Senate, the special election shall be held simultaneously with the succeeding regular election.