"She (Zille) is presenting herself as the new champion of the most marginalised in society, particularly the unemployed," Vavi told a worker conference in Centurion.

"She is trying to endear herself to this marginalised South African population that is beginning to lose hope because we don't have a solution."

He accused of Zille of pretence, saying she championed the cause of the unemployed for the sake of accolades and votes in the next election.

"In her small mind, she believes that the ANC is done and is finished without Cosatu. She is discrediting Cosatu to remove the stumbling block to her attaining power in 2014," said Vavi.

He cautioned that the tripartite alliance could only under-estimate the political threat posed by the DA at its own peril in future elections.

"Don't underestimate the fact that already, five percent of the blacks in townships are voting for the DA. It's not a small matter. It's time to say to all of us -- 'vuka ma ulele' (wake up)," he said.

"Wake up and smell the coffee, don't beat the messenger. We need to look at ourselves today against the image of Nelson Mandela. Only then will we understand the challenges we face," he said.

Vavi said his message was not only aimed at the African National Congress, but was equally directed to all members of the tripartite alliance.

"That message applies to the ANC, the SA Communist Party and Cosatu equally. Quite often we make the mistake of looking only to the bigger organisation, the ANC. We are not in a good space ourselves," he said.

The conference was hosted by the SA Commercial, Catering and Allied Workers Union (Saccawu).

Earlier, Vavi paid tribute to former president Nelson Mandela, saying Madiba was a genuine leader who put his life in danger to serve, expecting nothing in return.

"In 67 years of his life in public service, in our common struggle to build a non-racial democracy in South Africa, he understood that he would be failing humankind if he did not sacrifice with his own life," Vavi said.

"It is so important for us to speak about unity today, particularly at a time when we face a serious challenge of pretenders at all levels. Mandela is genuine, he never did things so that he would get some form of support."

Vavi said Mandela was not only an icon of South Africa, but Africa and the world.

He led delegates at the conference in singing "Happy birthday Madiba".

July 18 was declared Mandela Day by the UN General Assembly in November 2009. The first president of the new SA and revered statesman celebrated turning 94 on Wednesday.