South Africa’s highest court ruled on Monday that former President Jacob Zuma was ineligible to sit in parliament, a decision that could exacerbate political unrest in the country a week before a crucial national election.

The decision threatens the political future of 82-year-old Mr Zuma, a former anti-apartheid hero who once led the African National Congress (ANC) liberation party. Mr Zuma had a bitter dispute He joined the ANC last year after announcing his support for a new political formation.

The Constitutional Court overturned an earlier decision by a Special Electoral Tribunal and ruled that Zuma could not stand as a candidate in the May 29 election due to a previous criminal conviction.

Although Zuma cannot sit in parliament, his face will still appear on the ballot paper alongside his new party, uMkhonto weSizwe (MK), as he is registered as its leader, according to the South African Electoral Commission. However, he will be removed from the list of candidates to represent the party in the National Assembly, the commission said.

Zuma is a populist politician with a loyal following and his image could be enough to boost his party and damage the ANC, which is fighting to retain the absolute majority it has held since the dawn of democracy in South Africa 30 years ago.

The MK party condemned the court’s decision in a statement on Monday, calling the court’s judges “ten highly compromised and contradictory individuals” who wielded too much power within the country’s constitutional democracy.

The party called on its supporters to give the party the majority it needs to restructure the South African government. MK said that if it could win two-thirds of the 400 seats in the South African parliament – a near-impossible feat for the young party – it would install Zuma as president.

“This deeply flawed and contradictory ruling is not the end, but rather a defining moment that confirms that the MK Party is the right choice for poor and oppressed black people,” the party said.

Some analysts say this discontent could prove to be a blessing for Zuma and his party.

“I think he will build on that and use it to gain support,” says Hlengiwe Ndlovu, a lecturer at the School of Governance at the University of the Witwatersrand in Johannesburg.

Mr. Zuma resigned from the presidency in 2018 amid widespread protests against allegations of widespread corruption within his government. Three years later, he was convicted and sentenced to Non-statement at a public inquiry into corruption.

Zuma’s attempt at a political comeback poses a major challenge to South Africa’s young democracy.

Following his arrest in July 2021, he became the first former president to serve a prison sentence in post-apartheid South Africa. he was released just two months into his 15-month prison sentence. The Constitutional Court later revoked the parole, but Zuma then received a presidential pardon from his successor and later political rival, Cyril Ramaphosa.

The court’s decision was based on the length of Zuma’s prison sentence. Although he was granted a reduction in sentence, which reduced his prison term, he had been sentenced to 15 months in prison, which disqualified him from employment, the court ruled.

Under South African law, a person convicted of a crime and sentenced to more than 12 months in prison cannot become a member of the National Assembly. That applies to Zuma, said Judge Leona Theron in handing down the verdict.

Mr Zuma was “neither eligible nor qualified” to stand for election for the next five years after serving his sentence, the judge added.

During a marathon court hearing on May 10, Zuma’s lawyers attempted to compel the Constitutional Court judges to recusal themselves on the grounds that the same judges who had convicted him were now deciding on his eligibility for parliament. That argument was rejected.

Tembeka Ngcukaitobi, a lawyer for the Electoral Commission, which opposed Zuma’s candidacy, argued that the law banning convicted criminals from running for a seat in the National Assembly “is designed to protect the public from lawbreakers who are now posing as legislators themselves.”

Zuma’s decision to lead and campaign for an opposition party has sent shockwaves through South African politics. Founded in December, uMkhonto weSizwe has quickly become one of the most visible opposition organisations in an election in which 52 parties are vying for votes – a record.

South Africans are more likely to vote for a party than an individual, but MK appears to be banking on the appeal of a familiar face: Zuma’s likeness can be found on all of the party’s election posters and T-shirts.

The party has already gained a foothold in KwaZulu-Natal province, Zuma’s traditional stronghold. Polls suggest Zuma’s party could play the role of kingmaker in a coalition government in the province.

On the one hand, the party was able to win over voters who were uneasy about the ruling ANC, but on the other hand, it was annoyed by the support of smaller opposition parties that were hardly able to capitalize on the ANC’s dwindling support.

Over the weekend, Zuma took his campaign to Soweto, once the centre of ANC support in Johannesburg, South Africa’s largest city, where his supporters filled a football stadium. Despite the legal setback, MK party members vowed to continue their campaign.

“It was a shock,” said Lebogang Moepeng, a senior member of the MK party. After its victory in the electoral court, the party was confident that the Constitutional Court would rule in its favour, he said, adding that the party was prepared for these challenges.

“It would have been naive of us to form a party and not consider the risks involved,” said Moepeng. “Legal, political and others.”

Zuma’s arrest and detention in 2021 sparked deadly unrest, and observers fear his expulsion from parliament could lead to renewed violence. But on Monday, the MK party urged its members to remain calm and refrain from violence.

“Of course there will be great dissatisfaction in this regard,” because many will see the ruling as a sign that the courts are biased in favor of the ANC, says Moshibudi Motimele, a lecturer in political science and governance at the University of the Free State in South Africa.

If people believed that the courts were not independent, they might think: “We have to sort things out ourselves. And in South Africa, ‘sorting things out ourselves’ means violence.”

But Ramaphosa, the current president and incumbent, said in a radio interview: “I am not concerned about this incitement to violence.” He added: “President Jacob Zuma should be the only person who respects the rule of law.”

John Eligon reported from Johannesburg.