As Numsa head towards their special congress in Boksburg next week the tensions within Cosatu, and between Numsa and the SACP, are exploding.
The critical question that is up for debate at the congress is whether or not the union should break with the ANC and support another party or set up its own party.
If the union does decide to break with the ANC and set up a workers' party its political credibility, solid organisational base and capacity to generate its own resources from its members could enable a potentially serious challenge to the ANC.
The stakes are high and the fight has been dirty. There has been a public death threat against Numsa general secretary Irvin Jim from an SACP leader. Zwelinzima Vavi, who has strong support in Numsa, has warned that "The corrupt and self-serving oligarchs will ... not hesitate to hire assassins to murder us".
There have also been accusations of treason, not in the legal sense but in the moral sense of betrayal of the nation and its struggle. Gwede Mantashe has declared Numsa an "agent of foreign powers" and the union has charged the SACP with "providing cover for the continued domination of white monopoly capital and imperialism in our country".
Numsa and the SACP both insist that they are holding fast to the version of Marxist doctrine taught by the SACP and that their opponents are turncoats.
For Numsa the DA and the ANC have the same policies on "matters of socio-economic transformation" and the SACP is "an apologist for neo-liberalism" that is "deflating working class militancy".
Things have also got acutely personal. Blade Nzimande has declared that Numsa is driven by "an agenda informed by unbridled personal ambition and personal wealth accumulation".
In the union's view Nzimande is "an unreconstructed Stalinist" who needs to account for a string of nefarious dealings including the infamous black bag with half a million in cash.
This sort of vitriol is not surprising. Across space and time the kind of nationalism that assumes for itself the sole right to represent the authentic will and destiny of a people is, like the kind of leftism that assumes that it and it alone can solve the riddle of history and redeem the suffering of society, inevitably narcissistic and paranoid in equal measure. In both cases disagreement can only be read as betrayal and conspiracy.
And here and now contestation within the alliance, and the wider left in and out of the alliance, has often been grounded in a toxic mixture of intimidation, slander and patronage expressed through chunks of old dogma hurled at opponents like bricks rather than anything remotely approximating Karl Marx's youthful vision of "an association of free human beings who educate one another".
But beneath all the sound and fury there is an unfolding process that could carry real consequence. It's too early for anyone to offer any certainty on where the realignment of electoral politics currently underway will settle.
But if Numsa does break from the ANC and form its own party the possibility of an effective challenge to the ruling party from the left will certainly be enhanced.
However it should not be forgotten that Numsa and the SACP share much of the same political vocabulary, and express it in the same kind of stolid jargon ridden prose.
Numsa's discussion documents reveal a union resolved to take on private ownership of the means of production but not very interested in forms of life, work and struggle outside of the factory.
The union does not take the fact that in recent years the home and the community have become sites of intense struggle, in which women have often been prominent, seriously. It does not seem concerned about the repression of these struggles. In fact its vision is largely economic. It tends to assume that the state is the only serious vehicle for effecting change and it doesn't take politics particularly seriously.
There is no adequate recognition of the degree to which the political class has its own interests, how these have often been allied with those of workers in the public sector and what this means for political practice.
Moreover it has retained the SACP's fundamentally authoritarian idea that the working class, which is conceived narrowly, needs to be led from above by an enlightened vanguard. The union seems to want to become a more consistent version of the SACP rather than to affirm a democratic radicalism.
But if Numsa makes a break it will have to find allies. An obvious candidate would be Vavi whose own politics is quite different to that of Numsa in that he takes civil society seriously.
When civil society means, as it often does, that NGOs and their campaigns are substituted for popular organisations and popular struggles this is not helpful.
But when there is, at least in principle, a recognition that there are ongoing struggles outside of the workplace, and around a range of issues, this can enable a broader political vision.
And if Numsa does form a workers' party the nature of realpolitik is such that it will have to look towards popular struggles for support. The precise way in which this encounter would transform its various protagonists can't be determined in advance.
But one thing that is clear is that the emergence of new parties doesn't mean that we are necessarily taking great strides towards a more democratic society.
There are plenty of countries - like India, Italy or Kenya - where political multiplicity has generated more cynicism, and retreat into narrow pre-given identities, than light and air. And given the new ventures by Julius Malema and Kenny Kunene we can't be certain that more parties will automatically mean better politics in South Africa.
The emergence of a specifically workers' party does not guarantee any particular political outcome. The MDC in Zimbabwe has, for instance, had a very different trajectory to the PT in Brazil. And we should be mindful of the cases in recent years, particularly in Latin America, where the formation of left or workers parties has resulted in the capture of popular struggles and their diversion into electoral politics in a manner that has ultimately weakened these struggles.
We should not forget that in our own history trade unions were at their strongest when they sustained a degree of autonomy from the national liberation movement.
Similarly popular struggles outside of the ANC after apartheid have been at their strongest when they have sustained their autonomy from NGOs, parties and other little would-be vanguards.
But every time that new political organisations or parties emerge outside of the ANC the ruling party's capacity to cloak itself in the more or less sacred authority of the nation and the Stalinist fantasy of a science of the political that, wielded by a wise elite, can shepherd the masses to socialism and, thereby, redemption is diminished.
A workers' party could raise real questions about the subordination of workers, and perhaps society as a whole, to capital. It could arrive at a position where it could place real pressure on the ANC. And at a moment when millions of people make their lives amidst economic devastation and the ANC is engaging in outright repression, sometimes murderous repression, against popular struggles these prospects carry the possibility of real historical weight.
Pithouse teaches politics at Rhodes University.
Read more articles by Richard Pithouse.