Ultra-left political punk-pop act Chumbawamba have signed on to perform a Dec. 12 acoustic benefit gig at London's Mean Fiddler hall to raise awareness about the case of death-row prisoner Mumia Abu-Jamal, according to a venue representative. Abu-Jamal -- who last year issued an album of commentary, Mumia Abu-Jamal: Spoken Word, on Alternative Tentacles -- consistently has maintained his innocence in the 1981 murder of Philadelphia police officer Daniel Faulkner. Joining Chumbawamba on the bill will be art-rockers the Mekons, electronica act Alabama 3 and others.