JOHANNESBURG - South Africa's opposition Democratic Alliance (DA) on Sunday announced the collapse of a deal to have former anti-apartheid stalwart Mamphela Ramphele stand as its presidential candidate in upcoming elections against the ruling ANC.
It would have been the first time that the DA had fielded a black presidential candidate in an election, providing a shield against persistent charges they are a vessel for white interests.
Ramphele -- the partner of slain South African hero Steve Biko -- would have faced beleaguered incumbent President Jacob Zuma.
But the deal fell apart at a meeting on Sunday aimed at finalising terms of the agreement announced last Tuesday, DA leader Helen Zille said in a statement.
"Dr. Ramphele reneged on the agreement that she stand as the DA's presidential candidate, and that (her party) Agang SA's branches, members and volunteers be incorporated into the DA," she said.
"This about-turn will come as a disappointment to the many South Africans who were inspired by what could have been a historic partnership," Zille added.
Ramphele launched her own political platform, Agang, a year ago, but in a crowded political field the party has struggled to garner funds and votes.
In Ramphele, the DA appeared to believe it had found a leader who could nudge the dial in its favour, or at least neutralise the African National Congress's attack and tap into deep voter unease.
The ANC has been in power since the late Nelson Mandela became the country's first black president in 1994.
Ramphele last week described her move as "a historic moment".
"We are going to take away the excuse of race and challenge the ANC to be judged on its performance," she said at the time.
"We are taking away that race card and putting it in the dustbin."
But the ANC alleged that the DA was using her because of the colour of her skin.
Zille defended her party's unusual choice.
"It is rare indeed for a political party to offer the position of presidential candidate to a leader from another party, but we believed this move would be in the best interests of South Africa," she said.
"People are looking for a strong and united alternative to Jacob Zuma's ANC, and we felt that Dr. Ramphele would help us speed up the realignment of politics," she said.
"The DA negotiated with Dr. Ramphele in good faith. Indeed she is a long-time personal friend of mine and I sought to bring her into politics over many years," the DA leader said.
Zille expressed surprise and bitterness after concluding Ramphele had made up her mind about the deal. She accused Ramphele of saying one thing to the media, another to her Agang supporters and yet another to the DA.
"Dr. Ramphele has demonstrated -- once and for all - that she cannot be trusted to see any project through to its conclusion," she said.
"The DA will nevertheless continue with its historic mission to build a non-racial political alternative in South Africa," Zille said.
Ramphele responded on her Twitter account insisting: "There was no confusion. I remain committed and still am the leader of Agang SA. The focus was to work together in the election."
The DA had on Friday published a joint statement announcing that Ramphele would join its ranks Monday at a press conference in Johannesburg. DA statutes stipulate that only its members can serve as candidates under its banner.
But Ramphele had reacted quickly by saying that the statement had been published without her agreement and that she would remain the leader of Agang SA.
She spoke in a video message to her supporters of partnership with the DA, when the latter spoke of an integration of the two parties.
South Africa's general elections, whose date has yet to be announced, are due to take place in the second half of the year.