OPINION ON REHEARING
For the first time in this appeal, the appellees argue, in their fifth point of error upon rehearing, that this court erred in reversing this cause because section 26.07 of the Property Tax Code is unconstitutional with respect to counties because it violates article VIII, sections 1-a and 9 of the Texas Constitution.
Article VIII, section 1-a of the Texas Constitution, among other things, authorizes Texas counties to levy an ad valorem tax, in addition to other constitutionally authorized taxes, to be used for the construction and maintenance of farm-to-market roads or for flood control, except “as herein otherwise provided.” TEX. CONST, art. VIII, sec. 1-a.
This section also provides for a $3,000 homestead exemption for every homeowner and provides that the tax is not to exceed thirty cents on each one hundred dollars valuation.
Article VIII, section 9 of the Texas Constitution provides, among other things, that *484when the commissioner’s court meets to levy the annual tax rate, it shall levy whatever tax rate may be needed for the four constitutional funds (general fund, permanent improvement fund, road and bridge fund, and jury fund), so long as it does not impair any outstanding bonds, and so long as the total of the levies does not exceed eighty cents on one hundred dollars valuation in any one year. The section then provides that “once the Court has levied the annual tax rate, the same shall remain in force and effect during that taxable year.” TEX. CONST, art. VIII, sec. 9.
These provisions, then, authorize the commissioners’ courts of each county to set the tax rate, subject to the ceilings as stated. Section 9 of article VIII provides that once the rate has been levied, the rate set is to remain in effect throughout the taxable year. Such provisions are in conflict with section 26.07 of the Property Tax Code, which authorizes an election to roll back the tax rate which has been previously set by a commissioner’s court, regardless of whether or not the rate set is within the limit established by the constitution. We therefore find that section 26.07 is unconstitutional as applied to counties. TEX.TAX CODE ANN. sec. 26.07 (Vernon Supp.1988). For further discussion, see Op.Tex.Att’y Gen. No. JM-792 (1987).
The appellants contend that article VIII, section 21, was enacted more recently than sections 1-a and 9, and that its provisions authorize the tax roll back election system established by section 26.07 of the Property Tax Code, as applied to counties.
Section 21(a) of article VIII provides that taxpayers are entitled to certain notice when the taxes to be imposed by a political subdivision are greater than those imposed the preceding year. The subsection provides for a hearing before the subdivision increases the taxes. Section 21(b) excludes certain taxes from the computation. Section 21(c) provides that the legislature by general law is to require notice to taxpayers of any revaluation of their property and an estimate of how much their taxes would be if they were not raised. We see nothing in the provisions of section 21 which would contradict the provisions of sections 1-a or 9 of article VIII or authorize the tax roll back election system for counties.
Since we have found section 26.07 of the Property Tax Code to be unconstitutional as applied to counties, and because courts cannot compel a public official to act in compliance with an unconstitutional statute, Delta Cty. Levee Imp. Dist v. Leonard, 559 S.W.2d 387, 391 (Tex.Civ.App.—Texarkana 1977, writ ref’d n.r.e.), any error presented by the appellants’ points of error is harmless error because any such error did not cause an improper judgment. See TEX.R.APP.P. 81(b)(1). We therefore set aside our prior reversal and conditional order of mandamus and sustain point of error number five on rehearing. We overrule the remaining points of error on rehearing. We also overrule the appellants’ Motion for Summary Affirmation and Motion for Writ of Mandamus.
We set aside our prior judgment and affirm the judgment of the trial court.