The 19-4 vote by the National Executive Committee, with no discussion, brought John Lloyd's political career to an abrupt end on the grounds that he had "misled" the party about his role in sending a colleague to the gallows in 1964.
Mr Lloyd, 54, a barrister who fought the seat for Labour at the 1992 election, must have thought the memories of his earlier life as a member of the African Resistance Movement (ARM) were laid to rest.
However, he underestimated the determination of relatives and supporters of John Harris, a fellow-member of the ARM, who was hanged in 1964 for planting a bomb at Johannesburg railway station which killed a woman. Harris was convicted on Mr Lloyd's evidence - something for which he has always expressed remorse.
Tom Sawyer, general secretary of the Labour Party, is understood to feel that Mr Lloyd had not told the truth when it emerged that he could have withdrawn his testimony after he fled to Britain, which might conceivably have saved Harris.
The grievances of anti-apartheid politics have been replayed in dramatic fashion in the case. Many ARM partisans, including several who served long jail sentences in South Africa in the 1960s, emigrated to Britain.
Exeter Labour Party backed Mr Lloyd in his refusal to stand down after being invited to do so by the NEC in March. Local party members protested outside Labour headquarters in Walworth Road, south London, with proclaiming "John Lloyd - Exeter's choice".
The four voting against the decision were Dennis Skinner, the left-wing MP, Margaret Beckett, industry spokeswoman, Vernon Hince, of the Rail, Maritime and Transport union, and John Evans MP.
A party spokesman said there was no right of appeal and a new candidate would now be selected as quickly as possible.Reuse content