Miners (Gallo Images)

"The Mining Charter and the Immigration Act have contributed to the decline in migrant labour," she said.

Forrest said that at present 30 percent of all workers were migrant labourers, whereas most were migrant labourers in the 1970s.

She said mining companies were opting for locals as the mines would not provide accommodation for workers.

The mining charter also compelled mining companies to contribute socially to residents where they operated mines.

Migrant labour was minimal in the Rustenburg platinum mines, where 35 percent of workers were from the rural Eastern Cape.

She said South African mines had always relied on large amounts of unskilled labour to make profits.

"Recruitment systems and low wages are intimately interlinked, and recruitment was one of the pillars on which the migrant labour system rested."

She said the shift in recruitment had resulted in labour brokers making inroads into mines.

"Today, about a third of mine labour is contracted, numbering some 67,000 workers."

She said trade unions needed to revisit the central organising principle of equal pay for equal value.

"Unions need to organise proactively and intervene at the point of recruitment to demand transparency in negotiation of contracts and the setting of decent wage rates and conditions."

She said unions should also push for the provision of housing and services for mineworkers.