Virginia constitution
Article VII: local government
Section 6

Unless two or more units exercise functions jointly as authorized in Sections 3 and 4, no person shall at the same time hold more than one office mentioned in this article. No member of a governing body shall be eligible, during the term of office for which he was elected or appointed, to hold any office filled by the governing body by election or appointment, except that a member of a governing body may be named a member of such other boards, commissions, and bodies as may be permitted by general law and except that a member of a governing body may be elected or appointed to fill a vacancy in the office of mayor or board chairman if permitted by general law or special act.