Va. Code Ann. § 15.2-206

No bill to enact or amend a charter which has the effect of abolishing any office set forth in Article VII, Section 4 of the Constitution of Virginia shall be considered unless a referendum, elsewhere authorized by law, has been conducted in accordance with the provisions of § 24.2-685, and a majority of the qualified voters voting thereon have approved the request for the enactment or amendment of the charter.