JOHANNESBURG -  "This is a scandalous insult to the mighty union... which for decades has been fearless and unflinching in its defence of the most exploited section of the South African working class," Congress of SA Trade Unions spokesman Patrick Craven.

The National Union of Mineworkers (NUM) is a Cosatu affiliate.

On Saturday, Malema visited Marikana, where police shot dead 34 striking miners last week. He called on mineworkers to form a militant union that would represent their interests.

He said the union no longer represented the interests of the workers, but was interested only in making more money.

Craven said: "The federation deplores Malema's blatant opportunism in seeking to exploit the understandable concerns of the Marikana workers to score cheap political points."

The shooting on Thursday followed a week of violent protests which were believed to be linked to rivalry between the NUM and the Association of Mineworkers and Construction Union (Amcu) over recognition agreements at the mine. Workers also wanted higher pay.

On Friday, Amcu president Joseph Mathunjwa denied there was union rivalry, and said the NUM had "internal issues" which had nothing to do with Amcu.

He said Amcu had no affiliations with political organisations inside or outside South Africa.

The union was also not supported or funded by Malema, as had been rumoured.

"The allegations are baseless and unfounded. We have no political relationship with any political movement inside this country or outside," Mathunjwa said.