[3] He was one of the central figures in the "revisionist" school of South African historiography that, drawing on Marxism, revolutionised the study of the social formation of Apartheid by highlighting the importance of political economy, class contradictions and imperialism.
He then worked at universities in the United Kingdom and Tanzania, where he became active in the ANC and the South African Congress of Trade Unions (SACTU) in exile.
Together with Giovanni Arrighi, John S. Saul and others he developed an influential politico-economic analysis focusing on the contradictions engendered by the proletarianisation and dispossession of the Southern African peasantry.
In 1979, together with Paula Ensor, Dave Hemson and Rob Petersen, he was suspended from the African National Congress for allegedly forming a faction.
[10] However, he continued to play a leading role in the MWT of the ANC and was active in working class struggles in the Western Cape.