The Winslow Boy (1999) on Netflix

Early 20th century England: while toasting his daughter Catherine's engagement, Arthur Winslow learns the royal naval academy expelled his 14-year-old son, Ronnie, for stealing five shillings. Father asks son if it is true; when the lad denies it, Arthur risks fortune, health, domestic peace, and Catherine's prospects to pursue justice. After defeat in the military court of appeals, Arthur and Catherine go to Sir Robert Morton, a brilliant, cool barrister and M.P., who examines Ronnie and suggests that they take the matter before Parliament to seek permission to sue the Crown. They do, which keeps Ronnie's story on the front page and keeps Catherine in Sir Robert's ken.