2019 saw the Labour Party meet its fourth consecutive general election defeat, and its worst since 1935. Arguing that it is vital for Labour to regroup if it is to offer a serious alternative government, Lord Ashcroft draws on extensive research among real voters – especially those who have moved away from Labour in former heartland seats now represented in Parliament by the Tories. Diagnosis of Defeat explores the reasons for this extraordinary result and offers a frank and uncompromising portrait of the Labour Party as it is seen today.