He stood without success as a Labour party candidate in four parliamentary elections, in Leeds North-West in 1950; in Bath in 1951; and in Gravesend in 1955 and 1959.

He was made a life peer on 10 May 1978 as Baron Mishcon, of Lambeth in Greater London[4] on the recommendation of the Prime Minister, James Callaghan.

[citation needed] Mishcon was a board member of the Royal National Theatre 1965–90 and the South Bank Centre 1966–67.

He was chairman of the Institute of Jewish Studies, University College, London, and the honorary president of the British Technion Society.

He was a governor of Technion, Israel, president of the Association of Jewish Youth and of the British Council and the Shaare Zedek Hospital, Jerusalem.

Between 1984 and 1990 he had acted as a secret intermediary in negotiations between King Hussein of Jordan and the Israeli foreign minister Shimon Peres, offering the use of his country house.