The National Union of Metalworkers of SA has slammed Cosatu's endorsement of ANC deputy president Cyril Ramaphosa as the party's next leader after President Jacob Zuma.
The union expressed its disgust at its former alliance's decision to lobby for Ramaphosa when the ANC holds its elective conference in 2017.
"An ANC government led by Deputy President Cyril Ramaphosa will be no better than the one led by Jacob Zuma. It will do nothing to stop corruption and the looting of the country's wealth, which is not confined to a few crony capitalists and their political friends, but which is entrenched in the whole corrupt capitalist system," Numsa general secretary Irvin Jim said in a statement on Friday.
Numsa launched a scathing attack on Ramaphosa, referring to him as an "enemy of the working class".
This week, Cosatu endorsed Ramaphosa to take over from Zuma when his term expires in 2017.
This did not sit well with Numsa, who recently slammed Ramaphosa over the R3 500 proposed minimum wage.
"Cyril Ramaphosa has consistently attacked working class interests to benefit the capitalist class of which he has become a member. He was party to a negotiated settlement with white monopoly capital which left the economy owned and controlled by the very same capitalist class," Jim claimed.
"Worst of all, as a director of Lonmin, he was directly implicated in the massacre of 34 Marikana workers who demanded a living wage of R12,500. By now announcing a national minimum wage of R3,500, he is spitting on the graves of those workers who suffered exploitation until the oppressive agents of the capitalist state took their lives."
While Cosatu said it backed Ramaphosa because of his strong union roots and contribution to the country's Constitution, Numsa believed the democratic Constitution ensured black people stayed out of the economy.
"He ensured that there was a property clause in the Constitution which would keep ownership of the economy in the hands of South Africa's white, racist, capitalist, colonial elite - with a few black faces like his being co-opted to disguise this retention of the status quo," Numsa said.
Instead of backing existing parties, Numsa said, Cosatu should rather form a worker's party.
"It is high time that Cosatu and its affiliates, in particular members who are super-exploited by the capitalist class in South Africa, who are victims of mass poverty, mass unemployment and huge inequalities as a result of ANC and DA neo-liberal policies, wake up and accept that enough is enough," Jim said.
Numsa was expelled from Cosatu in 2014 after the union resolved not to support the ANC.