The actor and writer Chris Langham, who has died of pancreatic cancer aged 77, starred as the inept government minister Hugh Abbot in The Thick of It, the BBC television political satire created by Armando Iannucci. During its first two series, he was at the centre of chaos as the secretary of state in the fictional Department of Social Affairs, finding himself outmanoeuvred by his own political advisers and civil servants.

“Chris Langham is a master at acting the guy missing the point, out of his depth and striving to keep his head above water while sharks nibble his nether regions,” wrote the Sunday Times in 2005.

It seemed that Langham had put past demons behind him, but his time in the spotlight was abruptly cut short when he was arrested and then in 2007 jailed for downloading child pornography.

A quarter of a century earlier, alcoholism and cocaine addiction had led to Langham being sacked from Not the Nine O’Clock News, at the end of its first series in 1979 (and replaced by Griff Rhys Jones). Time in rehab was followed by writing for Alas Smith & Jones, which paired Jones with Mel Smith (1984-88). Langham later appeared in sketches alongside them in Smith & Jones (from 1989 to 1992).

“I was frightened that, clean and sober, I wouldn’t be talented any more,” Langham told the journalist Pauline Wallin in 1999. But his rehabilitation – and the satire – continued when he wrote Look at the State We’re In! (1995), a BBC series of six 10-minute skits confronting the laws and state powers governing modern life, with appearances from stars such as John Cleese, Hugh Laurie, Dawn French and Rik Mayall.

Hot on its heels, Langham was performing again, in John Morton’s award-winning BBC Radio 4 mockumentary People Like Us (1995-97), playing Roy Mallard, a bumbling journalist meeting people in different walks of life. The show then switched to television (1999-2001).

His big TV breakthrough in front of the camera was by then already under way, with him and Morton scripting the BBC sitcom Kiss Me Kate (1998-2001). He fed his own experience into the series, which starred Caroline Quentin as Kate Salinger, a counsellor, and Langham as her constantly depressed business partner, Douglas Fielding.

As this new-found fame made him in demand for press interviews, which inevitably brought up his troubled past, Langham reflected: “I could say I wish I wasn’t an alcoholic, but I am. It’s like being a diabetic. It’s not a moral failing on my part – it’s just the hand I’ve been dealt.”

He remained on an upward path. The BBC asked him to star as a psychotherapist in a sitcom, with his patients played by celebrities. He suggested: “Perhaps all the clients should be played by the same actor, in a Kind Hearts and Coronets sort of way.” So, in Alec Guinness mode, Paul Whitehouse stepped in, co-scripted Help (2005) with Langham (as Peter Strong) and not only took the roles of all the grotesque patients, with different wigs, prosthetic noses and accents, but also that of Peter’s own therapist.

The Thick of It then cemented Langham’s reputation as a naturalistic performer in satirical comedy and the honours rained on him at the 2006 Bafta awards, where he took the best comedy performance title for that programme and best comedy programme or series award for Help.

But Langham’s world had already started falling apart – he was arrested in 2005 on charges of downloading images and videos of child abuse. In court two years later, he denied the offences, saying he himself had no interest in children, but was researching material for a future episode of Help. Langham also claimed he had been sexually abused by a family friend as a child and that watching the videos was also an attempt to “reach something that I was blocking out”.

Langham was found guilty on all 15 counts, and not guilty on further charges of having sex with an under-age girl. He was sentenced to 10 months in prison, reduced to six on appeal. On his release he found work in just a handful of low-budget films. “Everybody in the country hates me – and I can’t get a job,” Langham told the Guardian in 2011.

He was born in London, to Michael Langham, a director in repertory theatre and later artistic director of the Stratford festival in Canada, and Helen Burns, an actor. Chris attended St Paul’s school, Barnes, while his parents worked in North America, and said he said dropped out of an English and drama course at Bristol University after suffering a nervous breakdown because of their subsequent marriage breakup.

He acted in fringe theatre and found work writing and appearing in sketches in Spike Milligan’s surreal TV programmes, including Milligan In… ( 1973) and Q5 (1975). Then, as a scriptwriter on The Muppet Show (from 1978 to 1981), he shared in a 1981 Primetime Emmy award.

As an actor, he had small roles in the films The Pink Panther Strikes Again (1976), Life of Brian (1979) and Carry on Columbus (1992), and character parts on television in Silas Marner: The Weaver of Raveloe (1985), The McGuffin (1986), Bergerac (1989) and Making Out (1990).

His marriage to the actor and singer Sue Jones-Davies ended in divorce. He is survived by his second wife, Christine Cartwright, a choreographer, whom he married in 1991, their children, Emily and Harry, and the three sons, Siencyn, Dafydd and Glyn, from his first marriage.

• Christopher Langham, actor and writer, born 14 April 1949; died 24 June 2026