If the Council fails to levy a rate of taxation at the time and in the manner provided by the Charter, the Controller shall add to the budget the amount required to meet maturing portions of principal and interest on the bonded indebtedness of the City and of special districts in the City, and any special taxes lawfully imposed, and shall calculate a rate of taxation as provided in Section 331, not exceeding the limit provided by law. The Controller shall give public notice of the rate of taxation by publication in a newspaper of general circulation in the City or by other means provided by ordinance, and the tax rate calculated by the Controller shall be the rate of taxation of the City. The Controller is hereby vested with all necessary legislative power to carry out the provisions of this section.