But in what appeared to be a contradiction on his part, the union's general secretary, Irvin Jim, said though Zuma was part of that collective, he must stay on for another term.

Addressing journalists in Johannesburg, Jim said the country was sinking in "the triple crisis of unemployment, poverty and inequalities" and that the ANC's leaders had failed to implement policies to deal with these challenges.

But Jim was unable to explain why Zuma should be spared the axe when ANC delegates converge on Mangaung in December.

"Numsa has done an assessment and from where we stand, we think the Polokwane leadership has not helped us, collectively, including comrade Jacob Zuma.

"However, in looking at leadership, there has been a debate and a position that was taken by Numsa and the view was taken that we can't do a clean sweep . Numsa took a view on President Zuma and we said we need to find new leadership that must surround him and that new leadership must take the country forward," he said.

Jim's contradiction comes at a time when the union has called for radical policy shifts, including a wholesale nationalisation of most of sectors.

While Jim failed to explain why Zuma should be exempt from being replaced even though he was part of the same leadership collective that had failed, he could only say Numsa's position was informed by trade federation Cosatu's resolutions taken its national congress in September.

The Times understands that Numsa had hoped to convince the congress to back Deputy President Kgalema Motlanthe to replace Zuma, but backed down in the wake of discussions to preserve the federation's unity.

With Numsa now backing Zuma, it is expected it will have a free rein in criticising him without being labelled anti-Zuma.

"Mangaung is about pulling together leadership. Numsa is part of Cosatu, so you're not going to have [a situation in which] Cosatu has pronounced but we differ with [it]," he said.