South Africa's President Cyril Ramaphosa promised his late predecessor Nelson Mandela on Friday that he would protect the African National Congress' absolute majority in next week's tightly contested election.

Ramaphosa staged his walkabout in Soweto, the town of his birth and a stronghold of the ANC going back to the days of the anti-apartheid struggle, to mobilise supporters ahead of a huge Johannesburg rally on Saturday.

In power since the advent of democracy in 1994, the ANC is still projected to emerge as the biggest single party after Wednesday's vote but could lose its outright parliamentary majority for the first time.

Ramaphosa promised that Saturday's rally would see him lay out a plan for victory.

"We have come to report to the legends of our movement, where our president Nelson Mandela used to live, to say: 'Don't worry president, the ANC is going to win this election'," he declared from the back of a truck amid crowds of supporters and Soweto residents.

"As I am here, I can already smell the sweet smell of victory, the sweet aroma of victory," he said, promising to lay out plans to tackle unemployment and corruption in his speech on Saturday.

- Last chance? -

The latest opinion poll from the Social Research Foundation (SRF) showed the party falling from 45.9 to 40.8 percent in a week, and even among the crowds waiting for the president in Soweto there were doubts.

"This is the last chance I am giving Ramaphosa's government because there are no jobs, there is nothing," said 44-year-old Boniswa Dludia, a qualified nurse whose last contract ended in September.

Portia Mohloane, 38, has been unemployed for seven years, and her loyalty to the party is slipping.

"The issues we are dealing with and they are talking about have been around since Mandela," she said. "They have enough time to make a change and our patience is running out."

Sliding under 50 percent would put the ANC in uncharted waters, forced to find coalition partners to remain in power.

"Everybody is aware that change is in the air and voting this time will make a change," said political analyst Sandile Swana. "There's going to be negotiation and this is not going to be like a regular election."

During Friday's event Ramaphosa received a boost on the foreign policy front when the International Court of Justice found in favour of a South African request for more interim legal measures to restrain Israel's campaign in Gaza.

But if the ANC is to rebuild an unassailable majority, it will have to remind sceptical voters of its domestic achievements.

The party is credited with winning freedom for black South Africans after decades of apartheid, building a vibrant democracy and lifting millions out of poverty by creating a broad social welfare system.

But many in the country of 62 million are fed up with high and still growing unemployment, currently at 32.9 percent, as well as rampant crime, corruption scandals, regular power cuts and water shortages.

The economy grew a meagre 0.6 percent in 2023.

- Stars and crowds -

About 27 million people are registered to vote on May 29. They will elect the 400 members of the National Assembly, which then chooses the president.

The largest opposition group, the Democratic Alliance, polls below 25 percent.

Led by John Steenhuisen, 48, a career politician advocating for liberal reforms including the privatisation of state-owned companies and the loosening of labour laws, it vowed to "rescue" South Africa and has formed a coalition with about 10 smaller parties.

The blue-branded DA will hold a rival event featuring a "star-studded musical lineup" in Benoni, west of Johannesburg, on Sunday.

It is trailed in the polls by the radical leftist Economic Freedom Fighters of firebrand politician Julius Malema, and uMkhonto weSizwe (MK), a new party fronted by former president Jacob Zuma that threatens to take votes away from the ANC.

Both hover at around 10 percent and will rally crowds of supporters in the northwestern cities of Polokwane and Emalahleni on Saturday and Sunday, respectively.

Once an ANC stalwart, Zuma fell out with his former party after being forced from office in 2018 under a cloud of corruption allegations.

This week he was ruled ineligible to stand for parliament because of a previous conviction for contempt of court, but Zuma remains his party's leader and his face will still appear on the ballots, which have already been printed.

In an interview with the BBC, Zuma denounced the ban, saying: "I'm going to fight it, because it's unfair as well as it is not a democracy."

Analysts believe the MK will not overly suffer from his exclusion, which the party has used to portray itself as a victim of powerful foes bent on preventing it from winning.

Colourful and charismatic, 82-year-old Zuma still musters considerable support among part of the electorate that views Ramaphosa, a multimillionaire businessman, as too business-friendly and detached.

Rioting after Zuma's brief 2021 imprisonment left more than 350 people dead. Ramaphosa has said the security forces were ready to deal with "any threat of violence".