Democratic Alliance leader Helen Zille has sketched three "frightening" scenarios of what might happen should ANC president Jacob Zuma be found guilty of corruption after becoming president of South Africa next year.

"We... need to ask what will happen if Zuma is found guilty if, as is likely, he is the president of South Africa when the judgment is handed down," Zille said in her party's weekly newsletter on Friday.

Zuma is to appear in the Pietermaritzburg High Court on 14 August this year on charges of racketeering, corruption, money laundering and fraud related to South Africa's multi-billion-rand arms deal.

Judgment in the matter may, depending on the length of the trial, be handed down only after next year's elections. Zille said in this event there were at least three potential "political solutions" available to Zuma should he be found guilty.

"The first is to use the ANC's parliamentary majority to pass legislation and/or change the constitution to grant a sitting president immunity from prosecution. This is the case in countries such as China, Chile and Sri Lanka."

She noted the prospect of the majority African National Congress "cynically changing the law to protect its president" would be unprecedented.

"The second possibility is that Zuma may use his presidential powers to give himself a pardon."

Zille said there were "already whispers about the prospect of a presidential pardon for Zuma".

Although there was no clear indication as to whether this would be constitutional, "this probably matters little to a man who has consistently said that the ANC is more important than the constitution".

The third option was for Zuma to use his presidential powers to appoint a new head of the National Prosecuting Authority willing to drop the charges against him.

"He [Zuma] will, no doubt, have no problem finding a loyal cadre willing to be deployed for this purpose.

"These scenarios are frightening, but all too real. If they came to pass, our hard-won efforts to secure constitutional democracy will have come to naught," Zille warned.

Sapa