Tenn. Code Ann. § 8-20-113

Notwithstanding any other law to the contrary, county governing bodies shall fund the operations of the county sheriff's department. The sheriff may appoint such personnel as may be provided for in the budget adopted for such department. No county governing body shall adopt a budget absent the consent of the sheriff, which reduces below current levels the salaries and number of employees in the sheriff's department. In the event a county governing body fails to budget any salary expenditure which is a necessity for the discharge of the statutorily mandated duties of the sheriff, the sheriff may seek a writ of mandamus to compel such appropriation.