Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 551. Interested members shall not vote;  penalty

A member who has a personal or private interest in any measure or bill proposed or pending before councils, shall disclose the fact to the branch of which he is a member and shall not vote thereon.  If such interested member shall vote without disclosing his interest in such measure or bill, and the same be carried by his vote, such member shall forfeit his office.