In City of Brownsville v. Public Utility Commission, 616 S.W.2d 402 (Tex. Civ. App.--Texarkana 1981, writ ref'd n.r.e.), a home rule municipality, argued that it was not subject to the jurisdiction of the Commission under the Public Utility Regulatory Act (PURA) relating to the extension of service into a certificated area of another retail public utility. 616 S.W.2d at 406-07. The question was the same as that raised here: whether the term "retail public utility" clearly and unmistakably included home rule cities so as to limit their plenary powers. Id. at 407. The Court concluded that the provision clearly and unmistakably limited the power of the city to extend service to areas being served by other utilities and constituted "a permissible legislative limitation on the otherwise plenary powers of home rule cities." Id.