South Africa’s powerful trades union federation, Cosatu, has called for President Jacob Zuma to step down.
Its Secretary General Bheki Ntshalintshali said he is no longer the “right person” to lead the country.
Mr Zuma has been under growing pressure following a major cabinet reshuffle which included the sacking of trusted Finance Minister Pravin Gordhan.
That led to South Africa’s credit rating being cut to junk status putting more pressure on a troubled economy.
Cosatu, a key part of the governing alliance, says it has 1.8 million members.
Last week, Deputy President Cyril Ramaphosa called the sacking of Mr Gordhan “totally unacceptable”.
In a speech at the weekend, which has been interpreted as a public broadside against Mr Zuma, he called for a renewal of the country and criticised “greedy and corrupt people”.
Former President Kgalema Motlanthe also said that it was difficult for Mr Zuma to command respect after the constitutional court found him in breach of the law when he failed to repay government money spent on his private home.