A statement from African National Congress secretary general Gwede Mantashe is unequivocal: "This act is anti-ANC and anti-revolutionary. This act is defamatory, insensitive and undermining of woman's integrity."
The fish-on-flesh question has raged in South African media in recent months following reports of the practice at parties of wealthy businessmen and socialites.
Earlier, Johannesburg newspapers had reported the head of the ANC's powerful youth league had attended such a party over the weekend.
Mr Mantashe added: "The ANC is not into nightclubs or partying, but it is a revolutionary movement."