Its leader, Zwelinzima Vavi, has been particularly outspoken about the failings of the government.

ECONOMIST: South Africa

"We are just too tired of getting blackmailed all the time, " Zwelinzima Vavi, the General Secretary of COSATU, told the BBC's World Business Report.

BBC: South African unions claim strike success

"No-one can tell me that raping a three-month-old baby or 87-year-old granny or burning a library or vandalising a school is caused by poverty, " said trade union federation leader Zwelenzima Vavi, in a recent Tweet exchange.

BBC: Will South Africans ever be shocked by rape?