The rapper took to the stage with a hype man and a string section wearing balaclavas for the performance, which aired on BBC Two.
Watch Plan B sing 'iLL Manors' live below:
The track serves as the lead single from his new album of the same name, as well as the title track for his forthcoming film.
The star - real name Ben Drew - recently admitted that he wants to "destroy" the music industry machine with his new LP, insisting that artists are no longer given space to air their political or artistic views.
Watch the iLL Manors film trailer and click through a gallery of stills from the motion picture below: