Johannesburg - Cosatu president Sdumo Dlamini on Tuesday called on unions which had aligned themselves to expelled general secretary Zwelinzima Vavi and Numsa to "free yourself".
"They have resolved that they want to break Cosatu into pieces," he said during his opening address on the second day of the federation's special national congress in Midrand, Johannesburg.
"I think comrades we must say no to that... we must free our unions. There is nothing like Numsa (the National Union of Metalworkers of SA) allies, there are Cosatu unions here."
Some delegates cheered while others booed while Dlamini ripped into Numsa, accusing it of trying to destroy Cosatu.
A group of unions, who called themselves the "Nine Plus" unions, wanted Vavi and Numsa to be reinstated into Cosatu.
The group had been boycotting Cosatu central executive committee meetings and had called for the special national congress because they wanted new leadership elected.
However, the Cosatu leadership had ruled that there would be no elections at the special congress, nor could Vavi and Numsa appeal to congress to return. This would be done at the normal congress to be held in November.
Dlamini said Numsa had been given ample time to review its positions, based on resolutions it had taken in December 2013.
"They refused. We protested Cosatu unions against cannibalisation against one union. If they (had) changed their ways and come and said 'we've changed', this congress would have (decided to address their issues at the November congress)," he said.
Dlamini said Numsa was attacking Cosatu and the affiliates supporting it were "embracing it".
"SA is a free country, you cannot get yourself to be a slave to another union, free yourself."