[2] Until his retirement in 1999, Birnberg was senior partner in the eponymous firm he founded in 1962, and he is considered a pioneer fighter against miscarriages of justice, who for more than 40 years "acted for clients ranging from the eccentric to the eclectic" – from high-profile cases to the "unfashionable".
[2][8] The Independent characterised Birnberg as having "acted for clients ranging from the eccentric to the eclectic – from high-profile cases such as Derek Bentley, Richard Branson and Vanessa Redgrave, to the 'unfashionable', as the solicitor himself describes Moors murderer Ian Brady.
Many notable solicitors started their careers with Birnberg, including human rights activist Gareth Peirce,[12] Imran Khan (who acted for the Stephen Lawrence case),[13] Jacqueline McKenzie (now associated with representing victims of the Windrush scandal),[14][15] and Paul Boateng, who went on to become in 1987 one of the first Black British MPs.
Boateng has described him as a "legal hero", writing in The Guardian:To work with Ben Birnberg was to occupy a world in which the clients were varied and the causes mixed and not always popular.
He struck a blow for artistic freedom, defending David Hockney's right to bring back magazines deemed obscene by customs and excise.