SACP general secretary Blade Nzimande lashed out at FW de Klerk on Thursday, branding the former president an "apartheid political dinosaur".
On Wednesday, De Klerk spoke at a briefing discussing the outcomes of the ANC's policy conference. De Klerk said the spirit of inclusiveness and reconciliation embodied by former president Nelson Mandela was no longer prevalent in the country.
He warned against the ruling party's national democratic revolution.
"The NDR as a concept is dangerous. A revolution against who? Who is the enemy?"
De Klerk added that the SACP was one of the driving forces behind what he called radical ANC policies.
Nzimande has since hit back, calling De Klerk "a politician who has long reached his sell-by date".
"All what De Klerk is saying about the SACP is nothing but an attempt at resuscitating the classical, but failed, apartheid 'rooi gevaar' tactic which was used by his now extinct National Party and its criminal apartheid regime not only to persecute communists but as part of the whole armoury to fight against the liberation movement," Nzimande said.
"De Klerk's latest anti-communist burst is nothing more than rehashing this nonsense, and in fact exposing that the likes of him no longer have any relevance in today's South Africa, if they ever did at all. Not so long ago he let the cat out of the bag by clearly stating he still firmly believes that the bantustan policies were the correct ones for South Africa."
In De Klerk's concluding remarks at Wednesday's briefing, he urged South Africans to be active and engage the ruling party on its policies, because they would shape the country's future.