Cosatu president Sidumo Dlamini warned on Saturday that it was cold outside the ANC and people should not run away from the party if they were unhappy.
“Challenges will always be there, but we must engage,” he told African National Congress supporters at the party's election manifesto launch in Nelspruit.
“We call on those who run away to come back. If you run away you can't engage.”
Dlamini said the Congress of SA Trade Unions would always support the ANC.
Last month, the National Union of Metalworkers of SA (Numsa) decided at its special congress not to support the ANC during this year's election. Numsa is Cosatu's largest affiliate.
Earlier this week there were rumours that Numsa was in talks with Julius Malema's Economic Freedom Fighters but this has been denied by both the union's general secretary Irvin Jim and the EFF.
Cosatu has also been dealing with its own internal battles after its general secretary Zwelinzima Vavi was suspended for having an affair with a junior employee, among other things. Both Vavi and Numsa have lodged court applications against Cosatu on the matter.
Dlamini on Saturday warned that Cosatu's unity was not for sale.
“The unity of Cosatu is not a playground... That unity we will defend with the last drop of our blood,” he said.
“Even when leaders go astray, it is workers' responsibility [to call] them to order.”
Dlamini said Cosatu endorsed the ANC's election manifesto and had participated in putting it together.
“We have carried a mandate from Cosatu... that we influence debate. We have engaged, we have fought, we have harassed each other to make sure [we do this].”
He said the trade union federation would help the ANC implement its manifesto. - Sapa