Local Government Code of 1991
Section 321. Changes in the Annual Budget. - All budgetary proposals shall be included and considered in the budget preparation process. After the local chief executive concerned shall have submitted the executive budget to the sanggunian, no ordinance providing for a supplemental budget shall be enacted, except when supported by funds actually available as certified by the local treasurer or by new revenue sources.
A supplemental budget may also be enacted in times of public calamity by way of budgetary realignment to set aside appropriations for the purchase of supplies and materials or the payment of services which are exceptionally urgent or absolutely indispensable to prevent imminent danger to, or loss of, life or property, in the jurisdiction of the local government unit or in other areas declared by the President in a state of calamity. Such ordinance shall clearly indicate the sources of funds available for appropriations, as certified under oath by the local treasurer and local accountant and attested by the local chief executive, and the various items of appropriations affected and the reasons for the change.