John Antrobus, who has died aged 92, was just 21 when in 1955 he joined the writers’ cooperative Associated London Scripts. Based in an office above a greengrocer’s shop in Shepherd’s Bush, it housed a cradle of talent shaking up postwar television and radio comedy.

Newly out of army officer training at Sandhurst, with a father who was a regimental sergeant-major and arriving wearing a herringbone suit, he found himself among a new generation sticking two fingers up at the establishment. He began by working with Johnny Speight, who went on to create the sitcom Till Death Us Do Part, and said that within months he had become more like his fellow writers.

With Speight and others, he scripted The Frankie Howerd Show on BBC radio over the next year (1955-56), but his most fruitful collaboration at Associated London Scripts – whose team included Eric Sykes, Ray Galton and Alan Simpson – came with Spike Milligan, who was enjoying success with Peter Sellers and Harry Secombe on radio in The Goon Show.

“Spike took a fancy to my work and we got on well,” Antrobus recalled in a 2015 radio interview. “He was very fatherly, really ... always telling me, ‘Look after your money.’ Then Spike asked me to work on The Goon Show.”

Antrobus, who loved the programme’s irreverence and surreal humour, scripted two 1958 episodes with Milligan, although he said he resisted offers to do more for the Goons because his ambition was to be a playwright.

This worked to his advantage when Milligan was commissioned to write a satirical play for the Tomorrow’s Audience theatre company founded by Richard Ingrams and John Duncan – and he needed help to meet a deadline.

The Bed-Sitting Room, set in London following a nuclear attack, with survivors believing themselves to be transformed into inanimate objects, was performed as a one-act play at the Marlowe theatre, Canterbury, in 1962 before being expanded and finding a wider audience at the Mermaid theatre in London the following year. It transferred to the Duke of York’s, then the Comedy theatre (1963-64), in the West End, and in 1969 was turned into a feature film, with the screenplay by Antrobus.

The writer recalled his years collaborating with Milligan – which included the star’s TV shows of the 1970s and 80s – in his book Surviving Spike Milligan (2002).

He also put words in the mouth of Sellers, jointly writing, with Galton and Simpson, the film The Wrong Arm of the Law (1963), and being called on to rewrite and invent scenes for Sellers’s final film, The Fiendish Plot of Dr Fu Manchu (1980). One new sequence had Burt Kwouk as the evil criminal’s servant bringing in a birthday cake with dozens of candles, and Kwouk’s costume catching fire.

Antrobus was born in Woolwich, south-east London, to Ada (nee Hopkins) and Arthur Antrobus, who served in the Royal Horse Artillery. As the family moved around, he attended Bishop Wordsworth’s grammar school in Salisbury, and Selhurst grammar school in Croydon, before going to King Edward VII Nautical College, London, when he worked as an apprentice deck officer in the merchant navy (1950-52).

This was followed by training at the Royal Military Academy Sandhurst (1952-55) while serving in the West Surrey Regiment. The actor Bill Kerr then introduced Antrobus to Galton and Simpson, who took him on at Associated London Scripts.

In 1956, when Milligan and Sellers wanted to transfer the humour of The Goon Show to television in The Idiot Weekly, Price 2d on ITV, with Richard Lester directing, Antrobus contributed material, as he did to its successors, A Show Called Fred and Son of Fred, both screened the same year, and the satirical That Was the Week That Was (1962-63).

On his own, he wrote the military film comedy Idol on Parade (1959) and episodes of the TV sitcoms Sykes and a … (in 1960), The Army Game (in 1960) and its spin-off, Bootsie and Snudge (in 1961).

He also created and scripted the sitcom Room at the Bottom (1964), starring Lionel Jeffries as an incompetent, washed-up television light-entertainment producer and Dick Emery as his boss. Later, when it was revived (1986-88) with James Bolam and Keith Barron taking over the parts of the producer and executive producer, Galton wrote the scripts. Antrobus also wrote a one-off comedy, An Apple a Day (1971), for Milligan, Dudley Moore and Peter Cook.

Throughout this time, he was fulfilling his ambition to write for theatre. Those plays performed at the Royal Court in London included Captain Oates’ Left Sock (1969, adapted two years later for BBC radio), about group therapy in a psychiatric clinic, and Crete and Sergeant Pepper (1972), set in a PoW camp following the Allied retreat in 1941. Hitler in Liverpool, at the Gate theatre, London, in 1980, imagined a supposed 1912 visit by a young Hitler to his half-brother in Britain.

Galton, following the retirement of his long-time writing partner Simpson in 1978, worked with Antrobus on several stage plays. When Did You Last See Your Trousers?, first performed by Theatr Clwyd in Mold in 1986, was a switch to farce, while Steptoe & Son in Murder at Oil Drum Lane, at the Theatre Royal, York, in 2005, revisited Galton and Simpson’s screen sitcom, although met with mixed reviews on reaching the Comedy theatre in London the following year.

In between, Antrobus and Galton wrote the TV sitcom Get Well Soon (1997), based on Galton’s post-second world war experience of meeting Simpson in a sanatorium while suffering from tuberculosis. Antrobus’s own triumph over ill health, at the end of the 60s, was recovering from alcoholism, a result of excessive drinking with his Associated London Scripts colleagues.

His CV also extended to the first and last Carry On films, writing additional material for Sergeant (1958) and Columbus (1992), and – while professing to be too shy to act – he occasionally popped up in cameo roles on screen.

In 1958, Antrobus married Margaret McCormick, with whom he had three children, Nicholas, Daniel and Louise; the couple divorced in 1980. Nicholas and Louise predeceased him. He is survived by Nicole Souchal, his partner of 35 years, and Daniel.

• John Arthur Antrobus, writer, born 2 July 1933; died 15 December 2025