Mandela celebrates his 89th birthday on Wednesday, at a time when the ruling party he once led is besieged by a fierce succession battle and the racial unity he so painstakingly forged during his presidency appears to be unravelling.

"The ANC misses someone like Mandela but he doesn't necessarily have to be Mandela himself but they have to find someone with ... magnanimity," said academic and columnist Xolela Mangcu.

"There are people out there who can play such a role. But I don't think the current lot (of leaders) are able to," he added.

Mandela stepped out of prison in 1990 after 27 years, preaching forgiveness to a starkly divided South Africa, which had barely escaped a bloody racial conflict before its first democratic election in 1994.

The final of the Rugby World Cup in 1995 delivered an enduring image of Mandela the unifier. Sporting a rugby jersey, he walked onto the pitch to congratulate a largely white team on its victory, with thousands of singing and cheering countrymen of all races ecstatically waving red, green, black and yellow flags as they looked on.

It was a fairytale moment for a country badly in need of hope after decades of violence and division.

By contrast, South Africa today is dominated by often bitter debates around affirmative action, crime and foreign policy -- all topics almost invariably split along racial lines.

Whereas Mandela went out of his way to reassure whites of their place in the "new" South Africa, his successor President Thabo Mbeki is often accused of fomenting division by accusing white critics of being racist pessimists.

Perhaps nowhere else is Mandela's absence more obvious than in the ruling African National Congress (ANC) -- the party that rallied the world to help end apartheid.

The ANC of Mandela's era counted the likes of Nobel laureate and ANC co-founder Albert Luthuli, respected leaders like Oliver Tambo, who commanded the world stage and mounted a global campaign to oppose apartheid.

Today, the ANC elite is bedevilled by corruption scandals and critics accuse it of abandoning the selflessness of the anti-apartheid movement as they jostle for power and a slice of the country's economic prosperity.

The leadership race has been marked by claims of dark political conspiracies, former ANC activists have been accused of being apartheid spies and the nation's spy boss was fired after he was accused of fabricating e-mails aimed at discrediting senior government officials.

As if wary of the gap that will be left by the father of the nation, Mandela's foundation has launched a series of projects to ensure his legacy is not forgotten, including an annual lecture, exhibitions and even a cartoon series.

While the prospects for the post-Mandela era do not appear too bright, Mangcu said the current tensions were an inevitable part of the young democracy's growing pains.

"It (Mandela's absence) has allowed us to grow and it has affirmed the principle that societies should never depend on one individual and no person has demonstrated that greater than Nelson Mandela," he said.