Thornton also played Truly in Last Of The Summer Wine, but it was his role as the disdainful floorwalker at Grace Brothers between 1972- 1985 that brought him the widest success.
As The Telegraph notes, “The imperious Peacock countered with dignity and moral distance the whims and wheezes of his underlings, notably the mincing Mr (“I’m free!”) Humphries (John Inman), the minxy Miss Brahms (Wendy Richard) and the purple-rinsed Mrs Slocombe (Molly Sugden) endlessly fretting about her “pussy”. In the face of insolence from insubordinates, Thornton could summon up a gesture or a look — shooting his cuffs, holding his head more erectly, casting a withering glare or just lifting a censorious eyebrow — to betoken multiple nuances of well-mannered disapproval.”
He later revived the role for the spin-off Grace and Favour.
Thornton began as a stage actor following training at RADA and also trained as a navigator in Canada and joined the RAF Entertainment Unit before returning to the stage.
His other television appearances included It’s A Square World, The Ronnie Corbett Show, The Goodies, Whodunnit?, The Tommy Cooper Hour, Steptoe and Son, Love Thy Neighbour, Bless this House, Morecambe and Wise, Til Death Us Do Part, Doctors, Holby City, Casualty, and All Rise For Julian Clary.
He made more than 50 films, among them Spike Milligan’s The Bed-Sitting Room (1969); No Sex Please We’re British (1973); The Three Musketeers (1973); and Gosford Park (2001).
His final role was 2012’s Run For Your Wife.