About 1,500 delegates from the ANC, which has ruled the country since 1994, were meeting at a policy conference to debate proposals that could block or clear the way for Mbeki to hold on to the reins of the party at a congress in December.

Mbeki must step down as the country's president in 2009, but the ANC's constitution does not prevent him from staying on as its leader and he has not ruled out another bid for the job.

Traditionally, the party leader is its candidate in presidential elections.

Some rank-and-file members this week have recommended that the party's constitution be changed to stop Mbeki, while others favour the status quo. A third group wants the party president and presidential candidate to be elected separately.

"I am certain that a consensus will be met (at the conference's general session)," ANC Secretary General Kgalema Motlanthe told journalists as delegates discussed the leadership dispute behind closed doors.

The four-day policy conference ends on Saturday when delegates are expected to issue several non-binding recommendations to help guide the party and its leaders during the next five years.

The prospect that Mbeki could remain as leader is anathema to many in the country's powerful trade union movement and Communist Party, which bitterly oppose his centrist, market-friendly policies and accuse him of failing the poor.

Many on the left have thrown their support behind former Deputy President Jacob Zuma, the frontrunner to succeed Mbeki until he was sacked in 2005 in connection with a corruption scandal.

The clash between the two ANC bosses -- Zuma remains deputy president of the party -- has plunged it into one of the most serious crises in its 95-year history and prompted rare discussion of a change to its constitution to settle the succession battle.

Motlanthe, however, said on Friday the party was loath to change its constitution for the sake of the nomination process, although he added that it was an option being debated.

It remained unclear what option the delegates favoured, and analysts said the party might choose a compromise that would satisfy supporters of Mbeki and Zuma as well as any other candidates that emerged in the coming months.

"They are trying to avoid polarisation of the party. So, there is ambiguity in presenting the three options," said Susan Booysen, a political analyst at the University of Witwatersrand in Johannesburg.

"They may be trying to keep the door open to Mbeki, but there is no way it will be just smooth sailing for him," she said.

The ANC, which came to power in South Africa's first all-race elections under anti-apartheid hero Nelson Mandela, dominates South African politics and its presidential candidate is virtually assured of becoming leader of the country.

The policy conference began during a four-week strike by public service workers that highlighted the fractious relationship between Mbeki's government and labour leaders.