Mosiuoa Lekota, the former South African defence minister, has threatened to split the ruling ANC following last month's ousting of Thabo Mbeki.
"It seems we are serving divorce papers," Mr Lekota said, after complaining at length about what he called undemocratic tendencies in the African National Congress, which he said had betrayed its principles. He announced a conference in the next few weeks where a decision may be taken to split from the ANC. President Mbeki's overthrow by the ANC leadership, the climax of a long struggle with the party leader Jacob Zuma, has caused the biggest political upheaval since the end of apartheid in 1994.
The ANC brushed off Mr Lekota's announcement, calling it a "machination". A spokeswoman, Jessie Duarte, said: "We will definitely not be deterred by the formation of new political parties."
Mr Lekota did not announce a new grouping as had earlier been predicted by local media, although he repeatedly said the ruling party, Africa's oldest, was near a split.
But he strongly indicated there could be a breakaway. "This is probably the parting of the ways... We hope that sense may still prevail in us... If not there's no going back," he said. He called for a meeting within four weeks of those who are opposed to the ANC's current policies and direction but said he had not spoken to opposition parties.
Flanked by another ANC dissident, the former deputy defence minister Mluleki George, he added: "Logically it seems that this is the end of it."
Investors are worried that Mr Zuma, backed by the Communist Party and trade unions, would push South African economic policies to the left if he becomes president after elections which are due next year. But analysts said Mr Lekota's announcement had not affected markets preoccupied by global turmoil.
It was not clear how much support Mr Lekota, a former chairman of the ANC, had, although he said hundreds of party supporters had resigned and regional and provincial ANC branches were contemplating leaving. Most analysts played down the impact of any breakaway party unless it was joined by ANC heavyweights, including Mr Mbeki. They said the party leadership might welcome the departure of dissidents to restore unity.
"The kind of breakaway possible under these circumstances will not make a significant difference," was the opinion of Steven Friedman, a political analyst at Johannesburg and Rhodes universities.
The South African Communist Party, one of Mr Zuma's backers within the ruling alliance, branded Mr Lekota as a right-winger. "Finally the beast is in the open," it said.
But the main opposition Democratic Alliance welcomed Mr Lekota's statement. "The disintegration of the ANC has begun, heralding an exciting new era," it said.Reuse content