"The flouting of one of the core founding principles of the federation, namely one industry, one union; the poaching of members; the cultivation of personality cults; the undermining of collective leadership and working class democracy; are all practices that play into the hands of the class offensive against the working class," he said.
"These practices must be unambiguously condemned and eliminated."
Accusations of corruption against Cosatu general secretary Zwelinzima Vavi earlier this year had reportedly divided Cosatu affiliates, and it was speculated they were part of a plot to oust him. Cosatu decided at a central executive committee (CEC) meeting last week that Vavi would keep his job.
Nzimande said the SACP was concerned about Cosatu.
"There must be unity in action," he said.
"It does disturb us when you hear some Cosatu affiliates talking at cross purposes, or even disagreeing with each other in public…. It might send a wrong signal at a wrong time."
Nzimande also condemned the "poaching" of union members.
There had been allegations that the National Union of Mineworkers and another Cosatu affiliate, the National Union of Metalworkers of SA (Numsa), were poaching each others' members in a fight for representation at Eskom. Numsa and NUM are Cosatu's biggest affiliates.
Last year, the NUM reportedly threatened to withhold its estimated R800 000 monthly subscription to Cosatu if it failed to intervene in its favour. Numsa denied poaching members. Cosatu president Sidumo Dlamini said at its bargaining conference in April that a number of Cosatu unions were guilty of poaching.
Nzimande said Cosatu could not allow the poaching of members.
"That, as far as we concerned as the SACP, will destroy Cosatu if it's not stopped.
One industry, one union was a large part of the negotiations that led to the formation of Cosatu, he said.
"Once you tinker with that, you are tinkering with the unity and almost the reason for the existence of Cosatu as a federation."
The SACP would raise this issue with Cosatu, said Nzimande. The party was telling Cosatu to "watch these problematic tendencies".
Talking about the National Development Plan (NDP), Nzimande said the plan should not become a monument.
"The NDP is an uneven document and the CC [central committee] welcomed the recent admission from planning commissioners that it is not written in stone, and that it is not perfect," he said.
One of the problems was that the NDP veered from general and unobjectionable vision, to long-range, unrealistic, or unambiguous targets, to an actual plan. Although the African National Congress adopted the NDP at its elective conference in December, it has been criticised by Cosatu and some of its affiliates.
Nzimande said the NDP should not become a "political football" which divided the alliance between the ANC, the SACP and Cosatu.
However, it was misguided to try and build alliance unity on the plan in its current form.
"We should rather seek to build unity in action around the ANC's key resolution on the need for a more radical second phase of transition," he said.
"Greater content needs to be provided to what is actually meant by such a phase, and any useful proposals within the NDP can, certainly, form part of such a strategic platform." – Sapa