He is married to Helen (née Conroy), one of their three children being Robert Peston, the BBC’s former business and current economics editor. The couple believed passionately in state education, and sent Robert to the local comprehensive, Highgate Wood School, in Crouch End, north London.
Peston founded the economics department at Queen Mary College, London, and advised various government departments and Labour Secretaries of State from the 1960s through to the 1990s.
Peston was created a life peer as Baron Peston, of Mile End, in Greater London on 24 March 1987. He immediately became Opposition Spokesperson for Energy (until 1997) and Education & Science (until 1997). He also served as Opposition Spokesperson on the Treasury (1990–92) and Trade & Industry (1992–97). He chaired the House of Lords Offices Refreshments Sub-committee from 1993 to 1997.
When Labour took over government, he chaired the influential House of Lords Committee on Economic Affairs from 1998 until 2005. Since then he has worked on the Lords Constitution Committee, and on the committee reviewing the BBC Charter