ANC MP Makhosi Khoza said on Saturday morning that it was wrong to celebrate this week's defeat of a motion of no confidence in President Jacob Zuma.
Khoza was delivering the keynote address on the second day of the Duke Menell Media Exchange in Johannesburg.
On Tuesday, Zuma survived a motion of no confidence in his presidency by 198 votes to 177, with 9 abstentions. The vote was secret.
About 25 ANC MP's voted against Zuma.
Khoza compared Tuesday's vote to other seminal moments in South Africa's political history, such as the jailing of former President Nelson Mandela in 1964, and the hanging of anti-apartheid activist Solomon Mahlangu in 1979.
"Those who celebrated the defeat on the motion of no confidence of the president on 8 August 2017 are mistaken. We must, as Amílcar Cabral told us before his assassination in 1973, 'expose the lies whenever they bear their ugly heads. Truth always prevails'."
She said those celebrating the defeat of the motion were on the wrong side of history.
"Those who celebrated in 1964 when Madiba was sentenced as a terrorist were mistaken. So were those who murdered and exiled our youth in 1976. Those who celebrated Solomon Mahlangu's hanging in 1979 were mistaken. History tells us so."
Following the defeat of the motion, the ANC said the vote had gone in the "best interest of the country and the electorate who gave us a mandate to continue improving their lives".
A 'dangerous ploy'
On Wednesday, ANC chief whip Jackson Mthembu said ANC MP's who voted against the motion had "allowed themselves to be used by the opposition to fracture and weaken the ANC and destabilise our country".
"We thank ANC members of Parliament who, in their huge majority, defended the democratic gains of the African National Congress and voted against the motion to remove President Zuma and our government," he said in a statement.
The ANC chief whip however, warned against compiling lists of ANC MP's who are purported to have voted against the president, saying this was a "dangerous ploy to incite mistrust and initiate a witch hunt".
On Saturday morning Khoza said that since publicly breaking ranks to speak out against President Zuma and others in the ANC leadership she had "once more become an exile".
"My life and that of my children are a living hell. I have not been to my own home for weeks for fear of my life," she said.
Khoza received death threats from an unknown number in the run-up to the vote, which she posted to social media.
Also read: Khoza death threat: 'You have 21 days'
She said she was committed to fighting for a non-racial, non-sexist South Africa.
"I am not prepared, no matter at what cost, to defend a family dynasty. I am not prepared to defend their cronies. I am not prepared to sell my people out."