The mood was ebullient Saturday among supporters of the man tipped to oust Thabo Mbeki as leader of South Africa's ruling African National Congress (ANC), as party members poured into the northern city of Polokwane to pick their president for the next five years.

Cattle herders leaning on their sticks watched as dozens of buses carrying delegates from across the country rolled past the waste ground where their animals were grazing to the University of Limpopo, venue of the 52nd ANC national conference starting Sunday.

Wealthier ANC members, nicknamed "black diamonds," had come in Hummer luxury four-wheeled vehicles and expensive jeeps.

"U Zuma, mufunu Zuma," (Zuma, we want Zuma,), groups of Zuma supporters chanted as they danced through the entrance of the university.

Tight security around the venue reflected the divisiveness of the first conference since 1949 where two candidates will go head to head for the leadership. Usually ANC leaders are selected by the party leadership.

If elected Zuma would be well placed, given the ANC's popularity, to become the third South African president since the end of apartheid in 1994. The first was Nelson Mandela from 1994 to 1999, followed by Mbeki, whose second term as president ends in 2009.

Mbeki's bid to remain on as party leader even though he cannot seek a third term as state president in 2009 has been slammed as reminiscent of the refusal of many African leaders to relinquish power.

A Zuma win appeared almost a fait accompli after he took nearly two-thirds of votes at the party nominations level.

But his progression to the presidency is far from assured. He faces corruption charges in relation to a state arms deal.

The National Prosecuting Authority said Friday it had gained access to more evidence proving Zuma, who was sacked as South Africa's deputy president in 2005 by Mbeki on suspicion of corruption, had received backhanders from companies while in government.

The leadership race has been characterized by a barrage of negative campaigning, unprecedented in ANC circles.

Mbeki has urged ANC members not to vote for "criminals and rapists" in what was taken as a reference to Zuma. In 2005, Zuma was acquitted of raping a family friend.

Zuma supporters on the other hand have denigrated the government's push for greater gender equity as "womanizing" and government propaganda as akin to that of Nazi Germany.

Several supporters of the popular 65-year-old Zulu politician had worn T-shirts marked "100%" above his image on the front and "Jacob Zuma for President" on the back in defiance of a party ban on T- shirts endorsing specific candidates.

Mbeki's centrist economic policies, widely credited with ushering in a decade of sustained growth, have been slammed by Zuma's left- wing supporters for failing to significantly dent poverty and unemployment.

Nearly 4,000 delegates at the conference, which runs through Thursday, will elect a six-member leadership and a National Executive Committee of 66 members.

They will also discuss policy matters, including land reform, the structure of the police and the establishment of a media tribunal.

The new president is expected to be known by Monday after a vote by secret ballot.