Take last Sunday's political-school meeting by the National Union of Mineworkers (NUM), attended by about 1000 workers in Carletonville. Not one speaker completed their speech without a reference to this upstart union, which has been winning over membership from the NUM in the platinum, coal and mining sectors.
During their speeches the president of the NUM, Senzeni Zokwana, and the general secretary of the South African Communist Party (SACP), Blade Nzimande, devoted a great deal of time to lamenting that Amcu was not a trade union, but a group of "vigilantes and liars".
Leaders of the NUM feel under attack from Amcu, not only physically, but also in terms of representation in mining structures.
Their response is to warn their members against abaxhoki (those who mislead) and to encourage their shop stewards to do a better job of providing a service to their workers.
Zokwana, who delivered his entire address in isiXhosa, was particularly pronounced on the dangers of Amcu, accusing it of lacking its own programmes.
"What they do, instead of raising problems with employers, is just run to workers and instruct them not to go to work," he said. "And when members are fired, they are nowhere to be found. Miners are then left on their own."
Zokwana also accused Amcu of "business unionism", saying Amcu president Joseph Mathunjwa owned five companies, a statement greeted with expressions of shock and disbelief in the crowd.
He went on to accuse the media of being dishonest in its characterisation of Amcu. "The media says Amcu is a militant union. Why can't they say it's a violent union?"
But Zokwana conceded that some of his union's wounds were self-inflicted: "Before our last congress, we had people making allegations that R6-million had disappeared and we were publicising people's salaries."
The members even decried Amcu in their singing: "Asiyazi lento le ifunwa ngu Mathunjwa [We don't know what it is that Mathunjwa wants"].
When Nzimande took to the floor, he did not mince his words, speaking out against Mathunjwa's union: "Comrades, we need to distinguish between a trade union and a group of vigilantes. Amcu is not a union and has never been a union. The best way to describe it is a vigilante union."
Nzimande said Amcu had coerced many to join it. "Some workers are in Amcu because of intimidation. We are asking law enforcement to act on this situation. We must be careful, but you can't keep attacking people without them retaliating. It's dangerous."
But he took the attack beyond Amcu, characterising it as only part of forces such as fellow Cosatu leaders, the media and mining houses that represent a threat to workers' interests and the ANC. He urged mineworkers not to be misled and to close ranks against these forces.
Independence in the alliance
Nzimande said some trade union leaders were attempting to drive a wedge between Cosatu and the ANC by continually criticising the ruling party.
"These habits of recklessly attacking the ANC are irresponsible. Those who say they do so because they are independent are wrong. There is no independence in the alliance."
Nzimande described the phenomenon of casting doubt about the ANC among workers as "Kadalism", referring to the leader of the previous century's powerful Industrial and Commercial Union, Clements Kadalie, who Nzimande said had tried to divide workers and the liberation movement and had been expelled from the union.
He told workers that in fighting corruption in the NUM and the ANC they must be careful not to project the organisations as corrupt themselves.
"Why is the media celebrating anyone who criticises the organisation? They praise everyone else in order to condemn the ANC. We are not paper heroes."
But Nzimande wants unionists to face up to their problems. "We will not defeat vigilantism if we do not improve our service to workers. The most serious threat to Cosatu is poor service to workers."