Democratic Alliance (DA) leader Helen Zille on Thursday dismissed President Jacob Zuma's attempts to place his love child in the context of Zulu culture, saying that it was no excuse for infidelity.

"No culture, polygamous or otherwise, justifies cheating on your wives," she wrote in her weekly newsletter SA Today.

Zille said that the scandal surrounding Zuma's affair and child with Sonono Khoza, daughter of soccer tycoon Irvin Khoza, was further proof of persistent abuse of power, both political and personal, by the President.

"Zuma believes he is above the law and social norms... the birth of his little girl in October last year neatly illustrates his abuse of power as a husband."

Zille cited culture expert Ndela Nelson Ntshangase, of the University of KwaZulu-Natal, as saying that polygamy was meant to provide every child with a steady home because illegitimate children were in a vulnerable position socially.

"And yet Zuma has tried to appeal to culture to defend himself. Like the race card, Zuma and the African National Congress play the culture card to try and silence legitimate criticism. This opportunistic strategy is actually an abuse of culture.

"Indeed, it is part of Zuma's pattern of power abuse. And it justifies further abuse of that culture by his supporters."

Zille said that Zuma was sending out a message that "it is okay to father as many children as you want, whatever the social consequences or cost to the State" and was setting South Africa back "at least a decade" in the fight against HIV/Aids.