(a) When approved at a referendum election held for such purposes in the manner hereinafter prescribed, any local board of education may divert any earmarked revenue derived by it from county sales and use taxes heretofore levied and imposed by local laws enacted by the Legislature of Alabama which exclusively earmarked such county sales and use taxes for capital outlay, construction and maintenance of public schools and use or spend the same for general educational purposes, including payment of teachers' salaries, other current school expenses, and costs of school transportation, the provisions of any general, special or local law to the contrary notwithstanding.

(b) Upon the written request of the local board of education to the county commission, the referendum elections referred to in subsection (a) of this section may be called, held and conducted as nearly as may be in accordance with state law. In counties which apportion such sales and use taxes between county boards of education and city boards of education under local laws or by agreement between said county and city boards of education, upon the joint written request of such county and city boards of education to the county commission, such referendum elections may be consolidated into one countywide vote, and the result of such consolidated election shall govern the permissive use of such earmarked revenue thereafter by both the county and city boards of education.

(c) This section shall not be construed so as to permit or allow the diversion or use for general educational purposes of any earmarked or dedicated school revenue derived by any local board of education from county sales and use taxes which have heretofore been pledged by such local board of education or other governing body to the amortization, payment or retirement of any school bond issue, school loan or school contract of any kind which calls or provides for the payment thereof from said earmarked school revenues.