The Commission for Gender Equality (CGE) welcomed the resignation of Deputy Minister of Higher Education and Training, Mduduzi Manana, on Saturday but said it had come a little too late.
"Consequently, this has created an unfortunate impression that government was morally ambivalent and indifferent about the seriousness of gender based violence," said CGE spokesperson Javu Baloyi.
"Mr Manana's resignation should not be exoneration for common assault and grievous bodily harm that he is charged with. Justice must be served for the victims of this attack."
Baloyi said the law must take its course, even if Manana remained an MP.
The commission appealed to all not to tolerate people who committed gender-based violence.
A "heartbroken" and "disappointed" Manana apologised to South Africans on Saturday after assaulting two women at a night club two weeks ago.
In a statement addressing South Africans, Manana, who did not initially resign after admitting to hitting the women, said there was no excuse for his actions. He said he was seeking professional help to "emerge as a stronger and better improved person".
He still wished to serve the public, he said.
"You [South Africans] have every right to be angry at me and I deserve your anger in this matter because no matter how you look at it, it was wrong in every way. To this extent, I am sorry. I take all accountability and I promise that this will never happen again."
He said there was "no excuse in the world to ever justify what I have done". He said women abuse was a serious issue.
Manana appeared in the Randburg Magistrate's Court on Thursday and was released on R5000 bail. He faces two charges of assault with intent to cause grievous bodily harm.
In a cellphone recording of Manana talking to one of the victims' brothers shortly after the assault, Manana says he slapped the woman because she called him gay.
Manana claimed he had been "extremely provoked".
The CGE urged members of the public with information about acts of gender-based violence and abuse to call its toll-free number on 0800 007 709. -- News24Suggest a correction