Johannesburg — AFRICAN National Congress (ANC) national executive committee member Fikile Mbalula has attacked former president Thabo Mbeki, saying he doubted the conspiracy against ANC president Jacob Zuma would have been exposed if Mbeki was still in office.

In an explosive 1800-word open letter to Mbeki, Mbalula said Mbeki's legacy was tainted with "shame" and "disgrace" as he presided over a period of gross abuse of state institutions.

"I doubt if today you were president this conspiracy that has come to light would have been uncovered," Mbalula said.

Mbeki spokesman Mukoni Ratshitanga said Mbeki would not comment on Mbalula's letter.

ANC spokeswoman Jessie Duarte said the ANC wanted everyone to move forward.

"Recrimination is not what we want. The ANC president has said ours is to build our institutions so as to never have this kind of abuse again," Duarte said.

Mbalula's attack, coming just before the general election, could provide impetus to the ANC to break its ties with the former president. Several of Mbeki's former ministers, including former deputy president Phumzile Mlambo-Ngcuka and former minister of public enterprises Alec Erwin, have endorsed the breakaway Congress of the People (COPE).

There was speculation early last month that Mbeki would come out in support of COPE days before the election.

Centre for the Study of Democracy director Steven Friedman said Mbalula's attack had to be read in the context of the poll.

"It's obviously an attempt to paint COPE with an Mbeki brush," he said. "The ANC wants to make it clear that it is the standard bearer for ANC voters, and that COPE and Mbeki are just sore losers."

Mbalula accused Mbeki of dereliction of duty, referring especially to his conduct when the security agencies became involved in the internal battles of the ANC's succession race.

Mbalula fingered Mbeki for blackening Zuma's name, and accused him of withholding critical information in the Schabir Shaik fraud and corruption trial.

He blasted Mbeki for "betraying the rule of law", which he said was the mantra of Mbeki's presidency. "It is a sad reality that the phenomenon we are dealing with today is a result of your actions of conniving and manipulating people, and advancing politics of patronage ," he said.

Mbalula also accused Mbeki of being the kingpin in the formation of COPE shortly after the ANC recalled him from office.

Mbeki's reaction to the abuse of power by former Scorpions boss Leonard McCarthy was telling.

"The more fundamental issue, which I would have expected would be your primary preoccupation, would be how did you fail the nation so badly such that the chain of events over the last nine years landed us in the position we find ourselves in today?

"How did the state apparatus become so embroiled in partisan politics that sought to rip our movement apart such that not even the highest office in the land had the political will to put brakes on the rot that was settling in?"

Mbalula listed a raft of claimed transgressions, including Mbeki's handling of the Hefer commission and the infamous off-the-record briefing of black editors. He accused Mbeki of inaction when the Scorpions acted illegally, and criticised Mbeki's endorsement of McCarthy, who went to the World Bank on leaving the crime-fighting unit.

Mbalula accused Mbeki of briefing ANC structures, the religious community and opposition parties (particularly the Democratic Alliance) on how corrupt Zuma was in an attempt to garner public support and sympathy.

"You were highly implicated as a central player in the compilation of a dossier which sought to defame Cde Zuma in the run-up to Polokwane, which was distributed among ANC delegates at conference," he said.