Cosatu's Sizwe Phamla says although the former president told the truth about Jacob Zuma being a poor leader, this is not what the country needs.
While the ANC says it accepts Mbeki's remarks and views them as part of robust debate, Cosatu says the former president has shied away from his own mistakes and has dwelled too much on comparisons between Jacob Zuma and himself.
Zuma defeated Mbeki 10 years ago, paving the way for his ascension to power.
Mbeki says what happened in 2007, when he lost to Zuma, was based on a fabrication of facts that fooled people such as Economic Freedom Fighters (EFF) leader Julius Malema.
The ANC's Zizi Kodwa says the party accepts everything that was said by Mbeki but wants to concentrate on 2019.
“We have gone past 2007, we are now preparing for the 54th national conference of the ANC.”
But Cosatu's Sizwe Phamla says although Mbeki told the truth about Zuma being a poor leader, this is not what the country needs.
“And he never acknowledged one little thing that he did wrong, which tells you that it is just an attempt to sanitise his own legacy. Of course, benefitting from the fact that President Jacob Zuma has turned out to be a worse president than president Thabo Mbeki was.”
Malema was one of those who led Zuma's presidential campaign, alongside former Cosatu General Secretary Zwelinzima Vavi and South African Communist Party General Secretary Blade Nzimande.
Both Malema and Vavi have since apologised for their hand in the campaigns, while Nzimande has said he felt betrayed by Zuma.