"NUM is the only best capable union to represent mineworkers in South Africa," he said.

Nzimande was addressing a Congress of SA Trade Unions (Cosatu) rally at Olympia Park Stadium in Rustenburg.

He said the SACP was concerned about some employers who were "conniving with some elements" to destroy NUM.

"They want to kill NUM by funding counter-revolution formations like AMCU (Association of Mineworkers and Construction Union)."

He thanked Cosatu members for their discipline and said that when a group of striking Anglo Platinum workers who opposed the trade federation charged at marching members, Cosatu remained disciplined.

"What I have seen is an extreme act of provocation, the police did well to disperse them," he said.

"I am interested to see how the media will report this."

Nzimande was speaking at a relatively empty stadium after a large number of Cosatu members ran away when police were dispersing striking workers who opposed the rally.

The group wore black t-shirts and said they would not return to work until their salary demands were met.