The ANC internal disputes affect the whole country, writes Joe Humphreys in Pretoria
For an organisation that likes to present a united front, South Africa's ruling African National Congress (ANC) is today in some turmoil.
Attacks from within the party against President Thabo Mbeki are becoming more frequent and bitter.
Tensions between left-wing and conservative members threaten to tear apart a traditional political alliance that helped to defeat the apartheid regime.
There is even talk of tribal rivalries surfacing in the selection of the next leader of the ANC, and by extension of South Africa.
It is a heady brew and the implications for the country - as well as for the African sub-continent, which looks to the so-called "Rainbow Nation" as a beacon of hope - can't be overstated.
Political analyst Prof David Welsh said disputes between the ANC leadership and its bedfellows in South Africa's governing tripartite alliance - the South African Communist Party (SACP) and trade union umbrella group Cosatu - were a regular feature of domestic politics.
"But I think they have been getting steadily worse. The volume, and rancorousness, of protest today has exceeded anything we have had since 1994. We have come closer to a break-up [ of the alliance] than at any previous time."
One of the most bitter exchanges came this week at a meeting of the ANC's executive committee. Mr Mbeki used the forum to accuse the SACP leader Blade Nzimande of "extraordinary arrogance" by daring to criticise the president's leadership style. Left-wing activists hit back in kind, with the SACP's youth branch describing Mr Mbeki as a "dictator" of the Robert Mugabe-mould.
Mr Mbeki suffered further embarrassment recently when supporters of former deputy president Jacob Zuma booed and interrupted the president's address at a public ceremony in Durban.
In addition, close allies of Mr Mbeki received unprecedented abuse at Cosatu's latest conference, while the president himself - a bookish figure who likes to pepper his speeches with quotes from WB Yeats - has been labelled "an absent father" by sections of the media.
The main destablising influence is the issue of who will succeed the 64-year-old former political exile as leader of the ANC - a position which, on previous form, guarantees the presidency of South Africa.
The last transfer of power from Nelson Mandela to Mr Mbeki was carefully stage-managed to minimise discord. But as yet there is no obvious replacement for Mr Mbeki, whose leadership of the ANC will be reviewed in December 2007 - two years before he is due to relinquish the country's highest office.
"Ideally, the ANC would like a unanimous decision but I don't think that's going to happen," said Welsh, professor emeritus of political studies at the University of Cape Town. "It's going to be very difficult to rig the process in any way."
Some party members are calling for more open competition, suggesting a run-off vote in the style of US party political primaries.
An election along these lines would help to strengthen democracy in South Africa, according to political analyst Steven Friedman. "There is a counter-argument," he said, "that you don't want to open up tensions, and if you let the genie out of the bottle the whole thing will go up in flames. But I don't think that is true."
Another democratic advance would be to have the president of South Africa directly elected by the people, said Prof Welsh. "There are insufficient points at which the electorate can choose the people for leadership positions - and this would be one way of changing that. But the impression I get from the ANC is that it is not on."
Indeed, there seems to be little appetite in the party's leadership to change either its voting system - which gives critical power to roughly 3,000 senior members - or its habit of withholding the declaration of candidates to the eve of elections.
"I think the ANC is going to run it like it has always run it," said Jeremy Cronin, deputy leader of the SACP, and a member of the ANC's national executive committee.
A veteran of the freedom struggle, he identified Mr Zuma - rather than policy matters - as "the divisive issue" in the tripartite alliance. "That division runs right through the ANC and the other partners," he said.
Mr Zuma, like all other potential candidates, denies harbouring ambitions for the presidency. ("There is a tradition in the ANC which says it's improper to campaign," Prof Welsh noted.)
But the former guerilla leader has already mobilised a vocal group of supporters to lobby on his behalf.
Among his backers are leading figures in Cosatu and the SACP, two organisations whose membership overlaps considerably with the ANC.
The politician, who was acquitted of a rape charge earlier this year, has been linked to allegations of corruption, and recently attracted negative comment for attacking lesbian and gay unions.
He has also controversially played the race card, drawing on his Zulu heritage to defend himself against various charges and suggesting, in the process, he is the victim of a political conspiracy.
His popularity has since risen among sections of South Africa's largest ethnic group who feel aggrieved that the country's first two black presidents have come from a Xhosa background.
Some are predicting a compromise whereby Mr Zuma will become party leader but not president of South Africa, leaving the job to a candidate more acceptable to both the public and the international community.
Others are predicting a split in the tripartite alliance, or even in the ANC itself, along either left-right, or socialist-nationalist, lines.
However, said Friedman, "it's way too early to talk about a break-up. You are dealing with an alliance of politicians who have spent all their adult life together in the same organisation and who believe it represents South Africa."
Cronin concurred, saying "the ANC is not an electoral choice but a family identity". Were the SACP to break away from the alliance and contest elections independently "it would be a one-way ticket into the political wilderness", Prof Welsh added.
In the short term then, South Africa's political fate is inextricably linked with the fortunes of Mr Zuma, and his rival factions. "Each camp is probing for the knock-out blow," said Mr Cronin. The longer the impasse continues the greater the risk of a power vacuum opening up - a serious concern for all interest groups. With major challenges to address on poverty, unemployment, HIV/Aids and crime, South Africa can ill-afford an absence of leadership. As Cronin put it: "A winner-take-all Shootout at the OK Corral situation at the end of next year would be disastrous. But there are forces pushing things in that direction."