The Strategic Dialogue Group (SDG), a collective of ex-ANC youth activists, has condemned former president Jacob Zuma's decision to walk out of the commission of inquiry into state capture, it said in a statement released by Professor Billy Ramokgopa on Friday.
The SDG, whose members were mostly leaders of student and youth organisations in the late 1970s, '80s and '90s, said Zuma had betrayed his oath of office.
Ramokgopa said Zuma's allegation of a political conspiracy had no factual standing.
"For more than a decade, Zuma himself has been a peddler of the narrative of 'political conspiracy' in an attempt to explain away his unending legal woes and to solicit sympathy from ANC members and the population. But one thing has been consistent: he has so far failed to provide evidence of such conspiracy before the courts and latterly, the Zondo commission."
He said that after retirement, former heads of state remain part of the nation's public life, "with many people continuing to look up to them for guidance".
"Unstatesmanly (sic) or indecent conduct on their part becomes a matter of public interest. For this reason, [we] unapologetically condemn Zuma's conduct, lest it come to be misconstrued as a heroic deed."
Ramokgopa said Zuma's conduct was part of "a deeply disturbing tendency by some leaders of the governing party".
"[Their] conduct communicates the vulgar message that there are two laws - one for ANC leaders and another for citizens who are neither members of the ANC nor connected to high-ranking politicians."
He said the many tainted ANC leaders attribute their problems to a "political conspiracy" when decisions by the prosecution authorities adversely affect them, their friends and associates.
"They... vilify such decisions with little if any facts, logic and rationality, in the hope that virulent factional politics and not the law will become the final arbiter of legal disputes."
Ramokgopa called on ANC members and activists to be cautious "of the peddlers of the narrative of political conspiracy".
"The cost of being hoodwinked by these confidence tricksters will be far reaching for the future of South Africa and its people. Lastly, we call on the Zondo commission to press contempt charges against Zuma. If this is not done, it will render the commission and the law impotent."
On Thursday, state capture inquiry chairperson Deputy Chief Justice Raymond Zondo dismissed Zuma's application for his recusal.
Zuma's counsel said his legal team will review Zondo's decision, with the former president leaving the inquiry without Zondo's permission.