An ANC backbencher branded South African President Jacob Zuma a disgrace on Tuesday, adding one of his own MPs to the long list of detractors of all colours and political stripes who want an end to his eight scandal-plagued years in office.

In a breach of party discipline that reveals the depth of anger within the African National Congress (ANC), Makhosi Khoza, a strident 47-year-old Zulu academic, chose Nelson Mandela’s birthday to denounce Zuma as an insult to the memory of democratic South Africa’s founding father.

“I am here to defend the ANC mission, and not a dishonourable and disgraceful leader,” Khoza told a conference of civil society groups, unions and business leaders pushing for Zuma’s removal in a no-confidence vote next month.

The 75-year-old’s time on power has been marked by economic stagnation and scandal, from a $16 million state-funded “security upgrade” at his home to allegations of graft involving his friends the Guptas, a family of Indian-born businessmen.

Both Zuma and the Guptas have denied any wrongdoing.

Echoing the private, moral anguish of many ANC cadres who have watched Africa’s oldest liberation movement decline under Zuma, Khoza – an ANC supporter since the age of 12 – said she could no longer follow the orders of a flawed leadership.

“The dilemma I had is this: what if such directives are morally bankrupt? What if such directives are directionless? What if such directives reflect arrogance, dishonesty, denialism?”

Zuma faces the no-confidence motion on Aug. 8, the ninth time the opposition will have tried to unseat him by peeling off dissidents from the ruling party, whose majority has so far protected him by closing ranks.

Next month’s vote could be different: the Constitutional Court has cleared the way for the Speaker to allow a secret ballot, though it is not certain she will.

Khoza has made clear she will break ranks. If 49 of the ANC’s 249 MPs follow suit, Zuma could be out.

Khoza said she did not know how many others would follow her lead, saying intimidation was preventing many from coming forward.

Mcebisi Jonas, a deputy finance minister axed by Zuma in March, told Reuters it was a “big number”. He has since resigned as an MP.

One other ANC MP has told Reuters they would vote for Zuma’s removal in a secret ballot. The South African Communist Party, whose 17 MPs back the ANC in parliament, said in April Zuma should resign.

“Clever Blacks”

Although Khoza’s stance has brought her recognition, it has come at a price.

Last week, she received a death threat saying she had 21 days left to live, evidence, she said, of the regression of South African public life since the heady idealism of the early days of the “Rainbow Nation” born in 1994.

“One does not expect this in a democratic, constitutional South Africa,” she told Reuters in an interview, saying it smacked of the dirty tricks, threats and murder against opponents that predominated under apartheid.

“I’m taken back to the 1980s,” she said, recalling fighting and assassinations in her native KwaZulu-Natal. “I had my home burnt down. I lost relatives. To relive the moment 23 years after democracy is unsettling.”

Khoza, an expert in Zulu linguisitics who holds a PhD in public administration, also ripped into Zuma’s apparent disdain for African intellectuals, as shown by his dismissal in 2012 of dissenting voices as the prattlings of “clever blacks”.

Zuma’s formal education ended at primary school.

“I am black. I am clever. I am smart, I am educated,” Khoza said, to cheers from the crowd. “Therefore there is absolutely nothing wrong with me.”

ANC chief whip Jackson Mthembu referred queries about Khoza’s comments to the ANC. “I don’t respond to Makhosi Khoza,” he said.

ANC spokesman Zizi Kodwa and Zuma spokesman Bongani Ngqulunga did not answer their phones.