Other notable film roles include Private Brigg in the comedy The Virgin Soldiers (1969), Dennis in Loot (1970) and Edwin Antony in Percy (1971).

Bennett's character, Ricki Tarr, was pivotal in the BBC serial adaptation of John le Carré's Tinker, Tailor, Soldier, Spy (1979).

In later years, he was often cast in villainous roles including Mr Croup in Neil Gaiman's Neverwhere (1996), Peter Baxter in ITV police drama The Bill (2002) and crime boss Jack Dalton in EastEnders (2003).

After a brief period working as a supply teacher,[5] Bennett won a scholarship to train at Royal Academy of Dramatic Art and performed in repertory in Salisbury and Leatherhead.

[7] His first film appearance was as Leonardo in the 1966 Italian Il marito è mio e l'ammazzo quando mi pare ("It's my husband and I'll decide when to kill him"), directed by Pasquale Festa Campanile, a comedy in which a young wife carefully plans to murder her husband, who is 40 years her senior, to marry a young beatnik.

[8] Bennett then starred as nervously virginal newlywed Arthur Fitton opposite Hayley Mills in the Boulting brothers' adaptation of Bill Naughton's play The Family Way (1966).

"[6] He was reunited with Mills and the Boultings in the psychological thriller Twisted Nerve (1968), playing Martin Durnley in what the British Film Institute has described as "one of cinema's most striking depictions of evil".

[12] He starred in the Ralph Thomas-directed sex comedies Percy (1971), in which he plays a shy young man who becomes the recipient of the world's first penis transplant, and The Love Ban (1973).

His Puck in a 1967 Edinburgh Festival production of A Midsummer Night's Dream was described by Illustrated London News as "the best since Leslie French".

In 1979, Bennett appeared as the field agent Ricki Tarr in Arthur Hopcraft's six-part BBC2 adaptation of John le Carré's novel Tinker, Tailor, Soldier, Spy (1979), playing the character with "an ever-thinning veneer of boyish charm masking years of self-delusion and betrayal" according to the BFI.

[21] In 1986, he played the investigative journalist Allan Blakeston in Paula Milne's single drama Frankie and Johnnie, a production he described as "one of the best things I've done in quite a long time".

[6][22] The following year, he played an architect whose reaction to urban violence is to steadily turn his suburban home into a virtual fortress in Andy Hamilton's black comedy Checkpoint Chiswick, part of the Tickets for the Titanic anthology series.

[7][24] He was often cast in unsavoury roles including club owner Arthur 'Pig' Mallion in Dennis Potter's final, linked television plays Karaoke and Cold Lazarus (both 1996) and the villainous Mr Croup in Neil Gaiman's serial Neverwhere (1996).

He appeared in Lock, Stock... (2000) as Deep Throat[26] and joined the cast of the long-running soap opera EastEnders in 2003, playing Jack Dalton – the ruthless gangland kingpin of Walford.