Local Government Code of 1991
Section 460. Manner of Creation. - A province may be created, divided, merged, abolished, or its boundary substantially altered, only by an Act of Congress and subject to approval by a majority of the votes cast in a plebiscite to be conducted by the COMELEC in the local government unit or units directly affected. The plebiscite shall be held within one hundred twenty (120) days from the date of effectivity of said Act, unless otherwise provided therein.