President Jacob Zuma will launch the African National Congress election manifesto to an expected audience of tens of thousands at the Mbombela Stadium in Nelspruit today.

He will appeal for unity and discipline within the revolutionary alliance of the ANC, the Communist Party and Cosatu-affiliated trade unionists in the wake of the decision by largest affiliate Numsa to ditch the alliance.

The metalworkers' union has overtaken the mineworkers (NUM) in membership terms and has challenged Cosatu to take a more independent, pro-worker approach.

It has announced that it will not campaign for the ANC in the forthcoming elections. Nor will it finance the party.

However, individual members will be free to campaign as they wish "in their own time and using their own resources."

Numsa held a special congress last month at which delegates unanimously accused the ANC and SACP of moving to the right and betraying the working class.

"It is clear that the working class cannot any longer see the ANC or the SACP as its class allies in any meaningful sense," general secretary Irvin Jim told the December special congress.

The union pledged to explore the possibility of building a pro-socialist workers' party and a movement for socialism, to gain control of Cosatu from below and to unite workplace and community struggles through co-ordinated mass mobilisation.

This break with the ANC-led alliance that spearheaded South Africa's democratic transformation has heartened every rag-tag-and-bobtail group posturing to the left of the SACP, seeking a working-class base to adopt their theories.

The Democratic Left Front, led by former SACP press officer Mazibuko Jara and academic Dale T McKinley, was quick out of the traps, speaking of "a spectre haunting the ruling class and government in South Africa."

It picked up on Numsa claims that the SACP had failed the working class by calling on "genuine socialists still inside the SACP to leave the party and embrace the Numsa-led initiative."

The Marikana Support Group, set up by former members of Britain's Socialist Workers Party, and the Workers and Socialist Party set up by Peter Taaffe's Committee for a Workers International are also hopeful of gaining a toehold.

The Numsa congress considered a paper prepared on the Economic Freedom Fighters set up by expelled ANC Youth League leader and former Zuma devotee Julius Malema, noting that the EFF ranks appeared to be "predominantly working-class youth."

However, the Numsa paper said that while the EFF was "explicitly anti-capitalist ... it is not socialist" and it drew attention to EFF commander in chief Malema's role as a "tenderpreneur" capitalist.

Despite this, the EFF claims to be targeting half a million members before this year's election and expects a link-up with Numsa.

"All working-class formations and revolutionary movements should be united in the anti-capital struggles," said Malema on Thursday.

Both the SACP and Cosatu have reaffirmed their support for the ANC, prompting secretary general Gwede Mantashe, the former SACP chairman and NUM general secretary, to make light of the Numsa decision.

He told a press conference on Tuesday, following a national executive committee meeting, that "when they said individual members can do what they want to do, it means metalworkers will campaign for the ANC."

Mantashe joked that, in terms of Numsa withholding finance, he was having difficulty thinking back how much the union had given the ANC since the last election.

"But it's symbolic for them to have that pronouncement that they will not give money to the ANC," he conceded.

SACP first deputy general secretary Solly Mapaila spoke out at the 19th annual commemoration of Communist legend Joe Slovo at Soweto's Avalon cemetery on Monday.

"In memory of Slovo, we must confront the political charlatans who have been trying by all means to co-opt and distort his contribution and works in our struggle in order to justify their deviationist tendencies," he declared.

"Contrary to mobilising against participation in the leaderships of the SACP, ANC and ANC-led government, Slovo mobilised in favour of that participation."

Mapaila appealed for members to go back to basics, working within trade unions to develop "an understanding of the role of the worker inside the trade union movement and in the broader national liberation and class struggles."

Young Communist League general secretary Buti Manamela quoted Slovo's view that the SACP did not have "a natural right to lead workers. We must be the vanguard not by law but through social mobilisation and acceptance."

Manamela urged involvement in the elections campaign "not as an act to get votes but as a means to renew our mandate as was given to Joe Slovo and Nelson Mandela in 1994.

"We cannot correct the falsehood that is spread about our movement through press statements, but only through direct engagements and contact with our people."

No-one seriously expects the ANC to lose the elections.

Even the most optimistic oppositionists speak of the party's share of the popular vote falling to around 55 per cent from 65.9 per cent in 2009.

But the divisions within its base support indicate a growing feeling that progress, while substantial by any yardstick, is still moving too slowly for the poor and unemployed.