Newell began to be seen frequently on TV, usually cast as a fat villain or in comic roles. Given his rotund appearance and ability for playing slightly stuffy types, he was a natural stooge in several comedy shows, first for Arthur Askey, in Arthur's Treasured Volumes (ATV, 1960), then for Jimmy Edwards in Faces of Jim (BBC, 1962), with Ronnie Barker also supporting.[5]
He was originally cast as one of the inept recruits in the first of the Carry On films, 1958's Carry On Sergeant but, according to producer Peter Rogers, Newell turned up on the first day of filming, only to recognise the real-life sergeant hired to drill the cast as the one who'd made his life hell in the Army. He then, so Rogers claims, got into his Rolls-Royce, drove off and was never seen again.[4]
In an interview with the TV Times in 1968, he claimed to have gained weight as a deliberate attempt to boost his career, marking him out for some niche roles.[6] In Who's Who on Television in the late 1970s, Newell described himself as "Actor with a weight problem—the more he diets, the less work he seems to get."
His most notable role was as "Mother", the spymaster in The Avengers.[4] He had previously appeared in two earlier Avengers episodes: "The Town of No Return" (Diana Rigg's debut) and, as a Minister of the Crown, in series five's "Something Nasty in the Nursery".
Later in life Newell succeeded in losing a substantial amount of weight, but this did not prevent his early death from a heart attack. He was married and had two children.[citation needed]