Hugh Grant (portraying Jeremy Thorpe) learned to play the violin specifically for a scene in which Thorpe and his mother (Patricia Hodge) play a violin/piano duet to impress Norman Scott (portrayed by Ben Whishaw). Hodge plays the piano, without the assistance of a double, in the scene.
A bill to decriminalize male homosexuality in the UK was introduced in the British House of Commons in 1966 but failed to get support. A second bill was introduced and passed as an Act of Parliament in 1967, legalizing private homosexual acts between consenting parties over the age of 21 in England and Wales.
Leo Abse, the Member of Parliament who was a famous crusader for homosexual rights, was 48 years old in 1965, a very smooth, cultivated and sophisticated Cardiff lawyer with a very posh accent. He is depicted in this segment by a seventy-year-old actor and is patronizingly depicted as very naive, possessed of a caricature thick Welsh accent and condescending and ignorant about homosexuality.
As Norman gets ready for bed as an overnight guest of Jeremy Thorpe's mother, he briefly picks up a book titled "Giovanni's Room" from the nightstand. "Giovanni's Room" is a novella written by American author James Baldwin and published in 1956. The themes of "Giovanni's Room" are identity and sexuality-- it tells the story of an American man who moves to Paris and his relationship with another man, named Giovanni.
According to Hugh Grant, filming the love scenes between Jeremy Thorpe and Norman Scott with fellow actor Ben Whishaw caused him to break out in a rash due to contact with Whishaw's beard.