Opposition leader Helen Zille accused the African National Congress on Friday of rewarding crime by putting Winnie Madikizela-Mandela and Tony Yengeni on the party's election nomination lists.

"Both of them were previously ANC members of parliament. Both abused their high office; both violated the trust placed in them by the public; and both have been rewarded for their malfeasance with another offer of high office," the Democratic Alliance leader wrote in her weekly newsletter.

She said it was fortunate that neither could accept the nomination and go on to become MPs because the law bars anybody sentenced to more than a year in prison without the option of a fine from holding a seat in parliament for five years after their jail term had expired.

"Even so, the fact that Madikizela-Mandela and Yengeni made it onto the ANC's nomination lists demonstrates an unacceptable level of tolerance for all that is dishonourable and disreputable in public life," Zille said.

"In fact, their untrustworthiness is not so much tolerated as celebrated."

Zille said the nominations were not surprising given the ruling party's steadfast support for its leader, Jacob Zuma, as he faces corruption charges.

"After all, this is a party that is determined to have as its presidential candidate a man facing 783 counts of fraud and corruption."

Zille said the DA would propose a law change to ensure that nobody convicted of corruption, fraud or theft could hold public office to ensure that Zuma if became president and was later convicted, he would have to step down.

A report that fraudster Schabir Shaik received R5 million rand in a secret deal with the state on interest earned on R34 million seized from him, was further proof that South Africa has adopted a soft attitude towards corruption, she said.

"Corruption is increasingly being accommodated and normalised.

"The other day someone said to me: 'I don't care if Zuma is corrupt, he has done a lot for us'. People don't seem to understand that when a politician is corrupt, he is stealing from them."

Madikizela-Mandela was given a six-year sentence for fraud and theft later reduced to three-and-a-half years suspended for fraud while Yengeni was handed a four-year sentence for fraud and corruption relating to the multibillion rand arms deal in 2004.

The ex-wife of former president Nelson Mandela won a place on the ANC's Gauteng list of candidates for the National Assembly while Yengeni's name appeared on the Northern Cape and Gauteng provincial lists.

At the ANC's national list conference on Saturday and Sunday, the party will screen nominated candidates to ensure that they meet the criteria.