April 20 (Bloomberg) -- The African National Congress, which led the fight to end apartheid, may be the biggest threat to South Africa’s democratic institutions even as it prepares for victory in April 22 elections.

The power struggle that ANC presidential candidate Jacob Zuma won against former president Thabo Mbeki has damaged the National Prosecuting Authority and the National Intelligence Agency, said David Unterhalter, a professor at the University of the Witwatersrand Law School. It also led the parliament to disband South Africa’s premier investigative unit.

At stake are the independent institutions and the separation of powers enshrined in South Africa’s constitution, which emerged from the negotiated compromise that ended white minority rule in 1994. The statute, agreed to by all the major political parties, was aimed at safeguarding democracy and ensuring that the country’s leaders didn’t abuse their power.

“Institutions have become subject to influence and political factionalism,” Unterhalter said. The ANC unfettered “would come to play a greater and greater role and it would simply be a case of who is in control of the party.”

Zuma, 67, a former ANC intelligence chief who spent a decade in jail for seeking to overthrow the apartheid state, is the favorite to become president: Opinion polls show the ANC will win between 60 percent and 66 percent of the vote, and the president is elected by parliament.

Mandela

Nelson Mandela, the country’s first black president, joined Zuma yesterday at the ANC’s final campaign rally at Johannesburg’s 60,000-seat Coca-Cola stadium, which was packed to capacity. Mandela, who turned 90 last year and has grown increasingly frail since stepping down as president in 1999, said in a pre-recorded message that the ANC’s primary task was to “eradicate poverty and ensure a better life for all.”

Zuma prepares to ascend to the nation’s highest office on May 9, a month after state prosecutors at the NPA dropped charges against him of taking bribes from arms dealers.

The NPA’s acting head, Mokotedi Mpshe, said that while the case was solid, he decided not to pursue it after Zuma’s lawyers presented him with intelligence-agency phone taps that indicated the chief investigator, Leonard McCarthy, was conspiring with Mbeki supporters to destroy Zuma politically.

Many legal experts say the NPA made a “bad decision,” Unterhalter said. The Supreme Court of Appeal has ruled in the past that a case isn’t necessarily wrongful even if brought for an improper purpose.

‘Fundamental Questions’

“It has created serious doubt whether the institutions that must function effectively and independently are able to do so without political interference,” said Jody Kollapen, a lawyer who chairs the South African Human Rights Commission, in an interview. “It raises fundamental questions about whether the notion of equality before the law exists for all South Africans.”

Among the consequences of the eight-year-old series of accusations and charges: Parliament in January disbanded the Scorpions, the Scotland Yard-trained investigative unit that filed the graft charges against Zuma. The ANC argued that it was too independent and inadequately supervised.

The National Intelligence Agency itself says some of its confidential phone-tap recordings ended up in the hands of Zuma’s lawyers. While those lawyers have refused to disclose how they obtained the recordings, it is illegal for the NIA to pass state intelligence to a private citizen or for a citizen to possess it.

Phone Taps

The agency’s inspector general is investigating why the tapes were made and whether they were handled properly, said Imtiaz Faizel, chief operating officer of that office, in a telephone interview.

ANC Treasurer General Mathews Phosa said the ANC continues to hold “the high moral ground” because it “brought democracy in this country against the most oppressive system in the world.”

Zuma’s escape from graft charges, as well as his acquittal in 2006 on a rape charge, may win him support from the ANC’s biggest supporters, the 41 percent of South Africans earning less than $40 a month.

“Zuma has captured the imagination of people, portraying himself as one of them, someone who has been the victim of the elite,” said Mark Gevisser, author of “A Legacy of Liberation, Thabo Mbeki and the Future of the South African Dream.”

The case against Zuma stemmed from alleged bribes of 4.07 million rand ($451,000) that he received from his financial adviser, Schabir Shaik, who was bidding to supply arms for the South African navy. Zuma has denied the charges.

‘Public Corruption’

Shaik, who was convicted of bribery, was freed on March 3 after serving 28 months of a 15-year jail term, on medical parole meant for the terminally ill. His doctors said he suffered from depression and high blood pressure.

“How are we going to deal with public corruption now: a cloud hanging over Zuma, prosecuting authority in tatters, the police are in disarray,” said William Gumede, the author of “Thabo Mbeki and The Battle for the Soul of the ANC.”

Zuma has made contradictory statements about the legal system.

“We will always uphold, defend and promote the constitution of our country and all our democratic institutions,” he said in an address at the ANC’s final campaign rally yesterday.

In an April 9 interview with Johannesburg’s Star newspaper, Zuma took aim at the Constitutional Court, the country’s highest court, saying “I don’t think we should have people who are almost like God in a democracy.”

To contact the reporters on this story: Karl Maier in Johannesburg at kmaier2@bloomberg.net

Last Updated: April 20, 2009 07:03 EDT