The mayor shall annually prepare and submit a proposed budget to the council. After public hearing the council shall adopt an ordinance providing the municipal budget. Adoption of the budget shall constitute appropriation of the amounts specified therein from the funds indicated. If the council fails to adopt a budget for the ensuing fiscal year by the first day of the fiscal year, the amounts appropriated for the preceding year shall be deemed to be appropriated for the ensuing year on a month-to-month basis until such time as the council adopts a budget. Every general fund appropriation shall lapse at the close of the fiscal year to the extent that it has not been expended or encumbered, except that an appropriation for a capital expenditure shall not lapse until the purpose for which it was made is accomplished or abandoned or until three years pass without any disbursement from or encumbrance of the appropriation. Any appropriation may be decreased or increased by ordinance amending the budget. Part or all of an unencumbered balance may be transferred by the mayor within an appropriation. No expenditure may be made unless the finance director or other designee of the mayor first certifies that there is a sufficient unencumbered balance in the appropriate allotment or appropriation. If the mayor shall disapprove of the budget adopted by the council, within 10 days of the time of its passage by the council he shall return the same to the clerk with written objections and the clerk shall bring this to the next meeting of the council. A majority vote of the total membership of the council shall be necessary to override any veto of the budget by the mayor.