Additional pledge of excise taxes.

(1) Any municipality may pledge the proceeds of utilities services taxes, cigarette taxes, or franchise taxes, as defined herein, or any other excise taxes or other funds which such municipality is authorized to levy and collect or will have available, as additional security for the payment of the principal of and interest on any revenue bonds issued hereunder, or for reserves for such debt service.

(2) In the event of the pledge of such utilities services taxes, cigarette taxes, franchise taxes, or other excise taxes as provided herein, such pledge shall be and constitute a valid and legally binding contract between the municipality and the holders of such revenue bonds as the case may be, and the municipality shall be obligated to continue the levy and collection of such utilities services taxes, cigarette taxes, franchise taxes, or other excise taxes in accordance with the proceedings which authorize the issuance of the revenue bonds for which such utilities services taxes, cigarette taxes, franchise taxes or other excise taxes are so pledged as additional security as long as any of said revenue bonds are outstanding and unpaid.

(3) It shall be the mandatory duty of the municipality, when it has so pledged any utilities services taxes, cigarette taxes, franchise taxes or other excise taxes as additional security for such revenue bonds to continue the levy and collection of such utilities services taxes, cigarette taxes, franchise taxes or other excise taxes in the manner provided in the proceedings authorizing the issuance of the revenue bonds for which the same are pledged, and to raise the rates of such utilities services taxes, cigarette taxes, franchise taxes and other excise taxes to the maximum rates permitted by the statutes or franchises in effect at the time of the authorization of such bonds to the full extent necessary to comply with such proceedings authorizing the issuance of such revenue bonds.

(4) The state does hereby covenant with the holders of such revenue bonds that it will not repeal or impair, or amend in any manner which will materially and adversely affect the rights of such holders, the duty and obligation and power of the municipality to levy and collect such utilities services taxes, cigarette taxes, franchise taxes or other excise taxes in accordance with the proceedings authorizing the issuance of such revenue bonds.