PRESIDENT Jacob Zuma and Congress of South African Trade Unions (Cosatu) general secretary Zwelinzima Vavi on Friday emphasised the need for unity in the ruling alliance, warning that deep divisions threatened its existence.

In its leadership year, the African National Congress (ANC) and its left-leaning allies are battling to contain deep divisions that threaten to cause rifts that will remain long after the December Mangaung conference.

They were speaking at the South African Communist Party (SACP) congress under way in Richards Bay.

"If it collapses, that is the end of the revolution in South Africa," Mr Zuma warned, referring to the ruling alliance, which includes the SACP and Cosatu.

Mr Vavi said "it would be naive" to think the alliance would always enjoy the confidence of its supporters, who continued to suffer long after freedom was attained in the 1994 elections.

"The biggest challenge facing the ANC and the rest of the democratic forces is not a lack of ideas but our failure to implement what has been agreed and to have the political will to implement what we know is politically and morally correct," Mr Vavi said.

He warned that there was growing social distance between the leaders and their followers. "There will be no economic transformation led by divided and factionalised organisations, which are devouring themselves," he said.

He also criticised the SACP's tendency of labelling others, especially those who disagreed with it. Instead, it should unify the alliance. "Our party must fight the temptation to slide into easy condemnation, sectarianism, and negative labelling of all progressive organisations, which it in fact needs to lead and mobilise against the capitalist system." He added: "The call we are making to you as communists, as the vanguard of the working class is a simple one - unify us, don't divide us."

Mr Zuma also criticised the SACP for crowing about its claimed influence in the ANC. "You influence, you don't talk about your influence. You are a loser if you announce your intention to influence others."

SACP leaders have been claiming that they have an influential role in the ANC-led alliance, and are preparing to influence policy and leadership decisions to be taken at Mangaung.