alternate term: program novel
“A novel dealing with a special social, political, economic, or moral issue or problem and possibly advocating a doctrinaire solution. If the propagandistic purpose dominates the work so as to dwarf or eclipse all other elements, such as plot and character, then the novel belongs to the realm of the didactic and probably cannot be understood or appreciated for its own sake as a work of art. It may be good propaganda and bad literature at the same time” (Source: Harmon & Holman, 412).
Examples: The Chamber and The Street Lawyer by John Grisham.