Frank Langella, Christopher Plummer enter HBO's 'Ali' bout

Frank Langella and Christopher Plummer have signed on to play Supreme Court justices in “Muhammad Ali’s Greatest Fight,” an original telepic HBO is developing.

Langella will play Chief Justice Warren Berger in the Stephen Frears-directed project, while Plummer will play Associate Justice John Marshall Harlan II.

Shawn Slovo penned the script, which depicts the machinations of the Supreme Court as Ali pursued conscientious objector status during the Vietnam War. Ali was convicted by a Houston court in 1967 and spent three years exiled from the ring as his case journeyed to the Supreme Court.

Frank Doelger, Tracey Scoffield, Jonathan Cameron and Frears are exec producing, with Scott Ferguson producing.