By Martin Plaut
BBC News, Cape Town
The formal launch of a party of defectors from the governing African National Congress (ANC) marks a decisive moment in the history of post-apartheid South Africa.
The Congress of the People (Cope) - led by Mosiuoa Lekota, a former defence minister, and Mbhazima Shilowa, an ex-premier of the region around Johannesburg - poses the first serious challenge to the ANC since it came to power 14 years ago.
In the 18 years since Nelson Mandela was released from jail, the ANC has gone from being one of the most successful liberation movements, with a leader revered around the world, to a deeply divided organisation, led by Jacob Zuma, who has faced charges of corruption and racketeering.
Three broad reasons are cited for the recent rift:
- Personality differences
- A left-right split over economic policies
- Ethnic divisions
A key development came during last year's ANC conference in Polokwane, when then President Thabo Mbeki lost his fight with Mr Zuma to remain party president.
Mr Zuma's supporters went on to force Mbeki loyalists out of key positions of power, and Mr Mbeki was forced to step down as president in September.
Furious at losing influence, Mr Mbeki's allies turned on their former comrades.
Among their accusations was that the pro-Zuma faction had allowed the ANC's allies in the South African Communist party (SACP) and the unions too much power.
Mr Lekota wrote that it was unprecedented for the SACP to hold the most senior offices within the ANC.
"The ANC is NOT the SACP," Mr Lekota wrote. "And the SACP is NOT the ANC."
Mbhazima Shilowa resigned from the ANC earlier this month
The dissidents maintained they are true to the ideals of the ANC, which had been taken over by the left.
In reply, Mr Zuma's supporters accused the dissidents of being bad losers and political opportunists, who left the ANC because they were denied access to government resources or patronage.
Mr Zuma said he was not surprised by the resignation of his former comrades, adding it had been in the air for quite a while.
"It is just disappointing that people who have been in the leadership, who have been leading people within the ANC, are not able to show leadership when they come across difficulties," he said.
Others went further, accusing the defectors of preparing to ditch the ANC because it is questioning the conservative economic policies adopted under Mr Mbeki.
"Their agenda is to sideline the working class," said Blade Nzimande, secretary general of the SACP.
The trade union movement, Cosatu, called Mr Shilowa a "whisky-drinking egotist", and a black sheep who had betrayed the movement.
"He changed from being a darling of workers to a member of expensive, elitist, whisky-drinking and cigar-smoking clubs," Cosatu said.
From this perspective the division in the ANC is a left-right split, with Zuma supporters on the left and Lekota supporters on the right.
In reality, the situation is more complex, with some alleging that tribal differences are at least in part responsible for the divisions.
Xhosas, used to holding influence under Mr Mbeki, were said to be angry at being sidelined under Mr Zuma, who is a Zulu.
Jacob Zuma and Mosiuoa Lekota in happier times
These were inflammatory statements, more often spoken behind closed doors than openly aired.
But Zwelethu Jolobe, who teaches politics at the University of Cape Town, believes this has been a significant element in the split.
"People have organised and used ethnic arguments or tribal arguments to garner support in the different regions of the country for these two factions," he says.
In the run-up to the launch of the new party a series of events were held.
Rallies took place around the country, at which supporters of the new party tore up or burned their ANC membership cards.
Mr Lekota spoke at these meetings, where his supporters wore yellow and white T-shirts carrying his image.
Wind of change
But the rallies were met with demonstrations by ANC supporters, some of whom chanted: "Kill Shilowa, kill Lekota".
ANC dissidents have worn T-shirts with Mosiuoa Lekota's image
Some meetings were attacked, and only police intervention prevented Lekota supporters from being injured.
The organisers of the dissident party complained that venues they had wanted to book were denied them.
The ANC condemned the violence and called for calm.
But the party also accused the defectors of intolerance for burning ANC emblems.
Cope's launch in Bloemfontein sets the stage for next year's national elections.
What no-one can yet predict is how much support the new party will win, or how fundamentally it might transform the country's politics.
But after 14 years of ANC government there is now a real wind of change in the air.