Jacob Zuma, the favourite to become the next leader of South Africa's African National Congress, has denied that he would change economic policy.
Winning the leadership would boost Mr Zuma's presidency chances
He is seen as the candidate of the ANC's left wing, which criticises President Thabo Mbeki for being too business-friendly.
Mr Mbeki said earlier the current acrimony in the ANC was the worst he has seen in his 50 years in the party.
The ANC is to choose its next leader at a meeting starting on Sunday.
Mr Zuma was formerly South Africa's deputy president but was sacked after being charged with corruption in 2005.
If he defeats Mr Mbeki in the leadership contest, he would be the strong favourite for the South African presidency after a general election that is due in 2009.
Mr Zuma told the BBC's Orla Guerin there was no need to worry about him changing policy.
"This is in fact an unnecessary concern," Mr Zuma said.
"The ANC is going to move as it moves, and change its leadership as the time comes, but keeping its direction - so nothing is going to change."
Under Mr Mbeki, South Africa's national income has grown steadily but many poor people, who vote ANC, complain that they have not benefited.
On Friday, South African broadcaster SABC reported that new allegations against Mr Zuma had been raised in an affidavit before the Constitutional Court.
But asked whether he would resign from his position if new corruption charges were brought against him, Mr Zuma said he would only do so if found guilty.
"Allegations don't mean the man is guilty," he said.
The two men were previously allies
"Why should I step down when charged?"
ANC structures in five of South Africa's nine provinces have indicated their support for Mr Zuma, in a contest that has become highly personalised.
In an interview in the Mail & Guardian newspaper on Friday, Mr Mbeki said the acrimony within the ANC had reached unprecedented levels in the run-up to the leadership contest.
"The conflict is new even to ANC members older than I am," the president said.
Meanwhile, in an interview with the same newspaper, Archbishop Desmond Tutu suggested neither candidate was fit for the job of leading the ANC.
"There are other candidates - why are we concentrating on those two only? Remember that I speak as a non-ANC member and I can't be prescriptive, but I have a deep sense of unease," he said.
"We don't seem to be talking about policy differences between the two leaders. It's merely a question of personality and how much attraction the one candidate has over the other."
Mr Mbeki has made a similar criticism, saying people should be "elected to positions in the ANC, not to lead factions".
Mr Mbeki and Mr Zuma, once close allies, publicly fell out in 2005 when Mr Zuma was sacked as deputy president over corruption allegations.
He could potentially still face charges in connection with a multi-million dollar arms deal.
Mr Zuma was also charged with rape but was acquitted - he says the charges were political.
Mr Mbeki has already served two terms and cannot lead the country again, but correspondents say if he were to remain ANC leader he would be in a good position to decide who succeeds him as national leader.