JOHANNESBURG (Reuters) -Six years after South Africa's scandal-plagued former president Jacob Zuma was pushed out of office, he is backing a new party against his longtime political home the African National Congress in this week's election.

Zuma's political return as the leader of uMkhonto we Sizwe (MK), a party named after the ANC's former armed wing, is significant since the ANC appeared set to lose its majority amid declining popularity. 

MK's share of the vote in Wednesday's election stood at 8%, trailing the ANC which was on 42.5%, early data from the electoral commission showed on Thursday.

Although 82-year-old Zuma is legally barred from standing for parliament due to a jail sentence, MK's emergence has disrupted the political landscape, testifying to his enduring influence particularly in his home province KwaZulu-Natal.

The MK was performing strongly in the populous eastern province where the major city of Durban is located, with 43.2% of the vote versus 21.7% for the ANC, the electoral commission data showed. 

An anti-apartheid veteran and Zulu traditionalist, Zuma has a strong following especially in rural areas due to his populist style and modest upbringing. 

He rose through the ANC to serve as deputy president of South Africa from 1999 to 2005 under former President Thabo Mbeki, but was dismissed when he was implicated in a graft trial relating to a $2 billion arms deal.

Corruption charges against him were dropped and reinstated multiple times amid claims of political interference, and the case is only scheduled to go to trial next year.

Zuma's nine years as president from 2009 were defined by what South Africans call "state capture" after an inquiry pointed to systemic corruption in which well-connected business people plundered state resources.

When the ANC eventually pressured him to quit in 2018, Zuma ranted to the state broadcaster for an hour about his treatment by the party he had served since he was a teenager, saying his comrades had not followed proper party procedure.

South Africa experienced economic stagnation during Zuma's presidency, which some critics characterise as a period of national embarrassment and accuse him of ignoring the greater good of Nelson Mandela's "Rainbow Nation".

Zuma was sentenced to 15 months in jail in 2021 for failing to appear at an inquiry into corruption during his time in power, although he only served two months before being released on medical parole. More than 300 people were killed in the riots and looting spree that followed his arrest.

THE GREAT SURVIVOR

Commentators wrote off Zuma's political career several times, but he proved them wrong consistently, earning himself the nickname of the "great survivor".

Soon after becoming president, it emerged that millions of dollars of public money had been spent on upgrades to Zuma's sprawling country estate, including a swimming pool that one minister justified as a fire-fighting resource.

Zuma weathered a no-confidence vote in parliament over the upgrades and paid back more than $500,000 after unsuccessfully trying to argue his case in the constitutional court.

Among a litany of other scandals, Zuma was charged with raping the HIV-positive daughter of a friend. He denied the accusation of rape and was acquitted, but he was ridiculed after saying he had showered after sex to reduce the risk of contracting HIV.

Ronnie Kasrils, a former intelligence minister who spent years in the ANC underground, has said Zuma is not the simple man he portrays himself to be.

"Astute and engaging from earlier days, along the way Zuma has become driven by a lust for wealth and power," Kasrils wrote in his biography of Zuma.

Using skills honed as the ANC's intelligence chief during apartheid, during his presidency Zuma silenced dissenting voices by promoting little-known officials to powerful positions in the security and intelligence portfolios.

He also ensured the top leadership of the ANC was controlled by loyalists.

Zuma's fortunes changed in December 2017, when his then-deputy Cyril Ramaphosa won an ANC leadership contest, defeating his ex-wife Nkosazana Dlamini-Zuma to succeed him as party leader.

Within months corruption charges relating to the 1990s arms deal were reinstated and a judicial inquiry started hearings into corruption during his presidency.

Zuma announced in December 2023 that he would not campaign for the ANC in the May 29 election and was instead backing MK.

Although the country's highest court ruled this month that he was not eligible to run for parliament, Zuma's photograph will still be on the ballot papers as he is MK's registered leader.

His response to the ruling, which cannot be overruled, was typically combative, and the potential for unrest from his supporters remains a risk around the vote.

(Reporting by Alexander Winning and Nellie Peyton; Editing by Emelia Sithole-Matarise)

By Nellie Peyton, Alexander Winning