Tennessee Code Title 1. Code and Statutes § 1-3-124

(a) Notwithstanding another law to the contrary, a cause of action exists under this section for any affected person who seeks declaratory or injunctive relief in any action brought regarding the legality or constitutionality of a governmental action of only a political subdivision of this state.  A cause of action does not exist under this section:

(b) As used in this section, “political subdivision” means a local governmental entity, including a city, town, metropolitan government, county, utility district, local school district, public building authority, and development district created and existing pursuant to the laws of this state, or any instrumentality of government created by any one (1) or more of the named local governmental entities.

(c) This section does not limit any other cause of action or waiver of sovereign immunity to vindicate rights under the Tennessee Constitution or the United States Constitution.