Me. Rev. Stat. tit. 35-A, § 1709

In addition to the limitations of Title 5, section 18, the Public Advocate or any employee of the Public Advocate may not have any official or professional connection or relation with, or hold any stock or securities in, any public utility or competitive electricity provider operating within this State; render any professional service against any such public utility or competitive electricity provider; or be a member of a firm that renders any such service.