"None of yesterday's Aids denialists must come and lecture us today on leadership when they have not accounted for the hundreds of thousands of deaths they left behind," he was quoted by the Sowetan newspaper as saying in Midrand on Thursday.

Nzimande said he was "slaughtered" by then president Thabo Mbeki when he spoke of the need to acknowledge that HIV caused Aids.

In 2000, Mbeki was criticised for his stance on Aids and was accused, along with health minister Manto Tshabalala-Msimang, of turning his back on the scientific consensus.

Nzimande said Mbeki, and Congress of the People president Mosiuoa Lekota, formerly an ANC cabinet member, had left "a highly questionable legacy".

Nzimande said there was a "demonisation" of Zuma as "every Tom, Dick and Harry including the dead that have woken up from their graves were crying lack of leadership."

Last week, Mbeki said the African National Congress's current leadership was losing its ability to provide direction to South Africa.

"I... [am] deeply troubled by a feeling of great unease that our beloved motherland is losing its sense of direction, and that we are allowing ourselves to progress towards a costly disaster," he said.

He was delivering the Oliver Tambo memorial lecture at the University of Fort Hare, in the Eastern Cape.