One of England's most versatile character actors. He began his professional career on the stage, performing with the Royal National Theatre and Royal Shakespeare Company. He also did steady work on television, working for such directors as Mike Newell and Stephen Frears. He made his film debut with a small part in Jerzy Skolimowski's The Shout (1978). He went on to work with Frears again in The Hit (1984) and with Terry Gilliam in Time Bandits (1981) and Brazil (1985), but it was through his collaboration with Mike Leigh that he first became known to an international film audience, starring in Leigh's Life Is Sweet (1990). He gained further visibility the following year with substantial roles in Neil Jordan's The Crying Game (1992) and Mike Newell's Enchanted April (1992), and subsequently in such diverse material as Woody Allen's Bullets Over Broadway (1994), Widows' Peak (1994), Richard III (1995) and Little Voice (1998), the last of which cast him as a seedy nightclub owner.

His breakthrough year was 2001, as he starred in three critically and commercially successful films: Bridget Jones's Diary (2001; Moulin Rouge! (2001), for which he won a Best Supporting Actor BAFTA award for his scene-stealing performance as Harold Zidler;  the biopic Iris (2001), for which he won the Oscar for Best Supporting Actor as devoted husband John Bayley to Judi Dench's Iris Murdoch, the British novelist who suffered from Alzheimer's disease.