This case is before us on petition for writ of mandamus wherein it is sought by the Relator to compel the Clerk of the Circuit Court of Volusia County to accept filing fee of $18.00 to qualify the Relator as a candidate for the office of County Commissioner of Volusia County.

The petition shows that the Clerk of the Circuit Court is demanding of the Relator the sum of $54.00 as a filing fee to qualify for such office and that the Clerk of the Circuit Court is acting under the provisions of Chapter 14680, Laws of Fla., Acts of 1931, which fixes the salary of the county commissioners of Volusia County at $1800.00 per annum.

The Relator contends that the chapter above referred to is a Special Law fixing the salary of officers and that the same is in violation of section 20 of Article III of the Constitution of Florida because the General Law of *Page 323 Florida fixes the salaries of county commissioners at $600.00 per annum.

Mandamus may not be invoked to require an officer to perform a certain act, unless it appears that it is clearly the duty of the officer to perform such act.

Chapter 14680, supra, purports to fix the salaries of the members of the Board of County Commissioners of Volusia County and the Clerk of the Circuit Court of Volusia County is without authority to hold the Act inoperative or invalid. See State ex rel. A. C. L. R. R. Co. vs. The Board of Equalizers of Fla.,84 Fla. 592, 94 So. 681.

The petition of the Relator fails to show that he has such an interest in the subject matter of chapter 14680, supra, as to place him in the status of one having the right to contest the constitutionality of that Act.

For the reasons stated, the petition for mandamus should be denied and it is so ordered.

WHITFIELD, ELLIS, TERRELL AND DAVIS, J.J., concur.

BROWN, J., not participating.