I heard talk about how we had to fight for ourselves. This was all new to me but I was interested in what they were saying. They were preaching unity and power.’ In these words, Moses Mayekiso recalled his first visit to the Metal and Allied Workers Union (Mawu) offices in the early 1970s. At the time, he had no idea that over the next twenty years ‘unity’ and ‘power’ would enable the union to transform thousands of South African workplaces and the apartheid landscape.

Numsa's steady accumulation of power followed decades of relative powerlessness for African and coloured workers. In the 1970s, trade unions were not recognised by the National Party government and were excluded from the collective bargaining structures of the Industrial Conciliation Act and other labour laws. Capitalising on their shadowy status, many employers refused to deal with them. Working class power was also weakened, as it had been for half a century, by the migrant labour system and racial cleavages in the workplace and the labour movement. The docile, bureaucratic white unions tolerated by the government either ignored black labour or exercised paternalistic control over ‘parallel’ organisations for black workers. The political unionism which arose in the 1950s had been smashed by a ferocious state onslaught on the African National Congress's labour ally, the South African Congress of Trade Unions (Sactu), after the banning of the ANC in 1960.

The rise and fall of Sactu formed an important ideological backdrop for the early metal unionists of the 1970s. Underpinning Sactu's relationship with the ANC, and their joint political campaigns, was the theory of ‘internal colonialism’ formulated by the SACP chair, Michael Harmel, which came to dominate left thinking. This held that South Africa consisted of a former settler, now permanent, white middle class which exploited the mass of rightless, indigenous black people. The first stage of struggle was to eliminate racial oppression through a national struggle waged by a class alliance. After the defeat of the white minority government, working class interests would diverge from those of the black bourgeois ie and a new stage of working class struggle would begin. Trade unionism was thus important, but secondary, to liberation politics. As a result, the slow, painstaking construction of workplace democracy was neglected by the Sactu unions.