Embattled South African President Thabo Mbeki on Sunday used a speech to members of the ruling African National Congress (ANC) meeting to elect a new leader to lash out at corruption in party ranks.

Mbeki is attempting to remain on as president of the party but is expected to be routed by party deputy Jacob Zuma. Zuma's victory was seen as almost assured after he took around two-thirds of the vote at the nominations level.

Speaking at the end of a campaign characterized by mudslinging and recriminations from both sides he also lamented the moral rot within the former liberation movement.

"This is the practice that again is entirely foreign to our movement - the practice of using untruths, of resort(ing) to dishonest means and deceit to achieve particular goals," he said.

Careerism, Mbeki maintained, was responsible for divisions in the ANC, he said.

"Because leadership in structures of the ANC affords opportunities to assume positions of authority in government some individuals then compete for ANC leadership positions," he said.

Companies sought out these ANC members "so that they can get contracts by hook or by crook," he added.

The remarks were seen by some as a swipe at Zuma, who was sacked by Mbeki as deputy president and charged with corruption in 2005 in a case that was thrown out of court over delays.

Zuma faces fresh charges for allegedly taking backhanders totalling over 4 million rand (580,000 dollars) in a state arms deal.

Mbeki also defended himself from charges that he has sidelined the party on policy making and was intolerant of criticism, saying: "All these are complete fabrications."

He was addressing around 4,000 delegates at the opening of the party's five-year leadership and policy conference at the University of Limpopo outside the northern city of Polokwane.

The ANC is in the throes of its worst crisis in the party's 95- year history, sparked by Mbeki's decision to seek a third five-year term as party leader, even though he is constitutionally barred from seeking a third term as president in 2009.

While his remarks on corruption met with applause and whistles from "Mbeki-ites" the parts of his 2.5-hours speech which focussed on his government's achievements, including growth averaging 4.5 per cent over the past four years and millions of households gaining access to electricity, received a luke-warm reception.

No sooner had his speech ended than Zuma supporters broke out in a thunderous rendition of the former ANC military commander's trademark song Umshini Wam (Bring me My Machine Gun).

The mood was rebellious on the opening morning of the conference with Zuma's supporters on the conference floor drowning out the more subdued Mbeki supporters in song and holding aloft a newspaper article with Zuma's face.

From the outset delegates distrustful of the Mbeki leadership threw down the gauntlet, demanding that vote-counting at the conference be done manually, and not electronically as planned.

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, barring a trial and conviction on corruption charges.

Zuma draws his support from the left-wing of the party and its alliance partners, the South African Communist Party and the Congress of South African Trade Unions, who see in the folksy politician a leader more amenable to their left-wing agenda.

Mbeki's third-term bid and his growing intolerance of criticism have swelled support for Zuma in recent months as a protest candidate.

Nearly 4,000 delegates will elect a six-member leadership and a National Executive Committee of over 60 members by Thursday.

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.