Socorro Mayor Trini Lopez quit Sunday night. He was elected last November.
Mayor Pro Tem Mary Garcia says Lopez faced a special council meeting Wednesday and possible sanctions over his alleged financial interest in a city contract.
Lopez says he's the target of retaliation for trying to stop alleged corruption in the El Paso-area city of about 32,000.
Socorro council members last year changed city elections from May 2012 to November 2013 and extended terms to four years without voter approval.
The El Paso Times reported Monday that such home-rule cities must hold an election to change term lengths. Lopez says Socorro should have held municipal elections this spring.