The part is played by the great Colm Wilkinson, who originated the role of Jean Valjean in London in 1985. In the film, the bishop is a character around which much of the plot pivots.
A sharp-eyed reader writes:
I’m not too much up on my pre-V2 vestments (and neither it would seem was the production designer), but I’m pretty sure that Colm as the bishop was wearing a dalmatic in the movie.
I worked with Colm in the Toronto production of Phantom for 4 years and his voice is incredible. The movie was amazing!
He included the clip below for proof (which includes part of a funny parody of “Bring Him Home”).