(AFP) - South Africa's ruling party on Friday launches a closely watched conference that looks set to re-elect Cyril Ramaphosa as leader, despite a tarnishing cash-heist scandal.

Some 4,500 African National Congress (ANC) delegates from across the country are due to vote during the five-day convention at an events centre near Johannesburg.

Ramaphosa is bidding to retain the reins of the African National Congress (ANC) as the storied party struggles with rifts and declining support after 28 years in power.

Portraying himself as a graft-busting champion, Ramaphosa took control of the ANC in 2017 after his boss Jacob Zuma became mired in corruption.

The party's majority in parliament means that it also has control over approving the national president.

But Ramaphosa's clean-hands image has been dented by allegations he concealed a huge cash burglary at his farm rather than report the matter to the authorities.

Despite this, analysts say the 70-year-old leader remains on track to win the party leadership election, expected to take place among delegates on Saturday.

"The ANC needs Ramaphosa. He will win," said political writer Ralph Mathekga. "Even those who hate him need him to win."

Outside the conference venue, decked out in the party's green, yellow and black colours, a group of delegates chanted in Zulu that Ramaphosa should leave the presidency over the farmgate scandal. They also sang a popular pro-Zuma song.

On the eve of the conference Zuma announced he is suing Ramaphosa over a leaked medical report linked to a 1990s arms corruption trial.

But the lawsuit is unlikely to hamper Ramaphosa's chances of securing a second term as ANC leader.

A victory would secure him a ticket to a fresh term as president after the 2024 elections, if his party wins that vote.

- Reprieve -

Ramaphosa won a reprieve ahead of the conference when the ANC used its majority in parliament to block a possible impeachment inquiry.

He is leading the list of only two nominated presidential candidates so far and is seen to be the most viable in the absence of better options in the 110-year-old party.

The former trade union leader fronted the historic negotiations to end apartheid and helped draft the constitution -- hailed as one of Africa's most progressive charters.

Dodging the impeachment bullet "probably strengthened his bid to seek re-election" because it removed any "immediate uncertainty," said political analyst Susan Booysen.

His rival is his former health minister Zweli Mkhize, who has corruption allegations linked to Covid-19 funds hanging over his head.

"ANC members can be dishonest but they are not idiots -- they know that Zweli Mkhize is not a bankable star," said Mathekga, author of "The ANC's Last Decade".

- Decline -

The venerable party was shaped by Nelson Mandela into the main weapon that ended apartheid.

But its image today is stained by corruption and factionalism.

Protests spiralled into looting last year when Zuma was jailed for contempt of court for snubbing a probe into state corruption.

Ramaphosa told a party fundraising dinner Thursday night that the conference was "a watershed moment" for the ANC and South Africa.

His government has had to "steer the ship through stormy and unexpectedly rough waters," he said after listing Covid, the riots, floods and Ukraine war-induced cost of living crisis.

The ANC has also experienced its own "turbulence", he admitted. The conference will "determine where South Africa goes not only the next five years but in the next decade and beyond that," he said.

Over the past decade, the party has lost its grip over key cities in municipal elections.

Its showing in this battlefield slumped last year under 50 percent for the first time.

On a national level, the ANC won the 2019 election with 57.50 percent of the vote, down from 62.15 percent in 2014.

But it remains South Africa's largest party with 230 out of 400 seats in the National Assembly.

Whoever emerges victorious in the vote will have to defuse anger at crippling power cuts and entrenched poverty.

© Agence France-Presse