Mr Zuma was the country's president between 2009 and 2018.

He said it "would be a betrayal" to campaign for the ANC of current President Cyril Ramaphosa.

Mr Zuma's new party is named uMkhonto we Sizwe (MK), meaning spear of the nation, which is the same name as the former armed wing of the ANC.

In an incendiary statement, he said: "The new people's war starts today. The only crucial difference is instead of the bullet this time we will use the ballot."

The paramilitary MK, of which Mr Zuma was a member, fought the apartheid-era government of South Africa. It was formally disbanded in 1993 prior to the democratic elections which saw the ANC come to power under Nelson Mandela.

At a news conference in Soweto, Mr Zuma said he was not well enough to speak at length and one of his daughters read a statement on his behalf.

The statement said the ANC was "one of the great liberations movements of our time", but that it "truly saddens me that the ANC of today is not the once great movement that we loved and were prepared to lay down our lives for".

"I will die a member of the ANC," his statement said, but that it had "changed into an organisation we no longer recognise".

He said some leaders were behaving in an "un-ANC manner" and he intended to "rescue" the organisation.

He said the ANC was expected to lose the elections next year and referred to a "deliberate plot to kill the ANC". His statement characterised the current government as a failure.

He said President Ramaphosa was a "proxy of white monopoly capital" and that the "ANC of Ramaphosa has declared war against black professionals and intellectuals".

"I cannot and will not campaign for the ANC of Ramaphosa".

Cyril Ramaphosa (L) served as deputy president of both South Africa and the ANC under Jacob Zuma (R)

Doing so would lead to failure and a government by "sell-outs and apartheid collaborators", he said.

Instead, he would vote for the newly registered MK party, he said.

"No force can defeat the people's thirst for freedom," he said.

Mr Zuma's statement also referred to the "enemies of our people operating among us" and said "there can never be reconciliation without socio-economic justice and equality".

During the apartheid era, Mr Zuma was an anti-apartheid activist and spent a decade in jail as a political prisoner.

His time as president was controversial and included multiple allegations of corruption. He resigned in 2018 amid significant pressure from within the ANC and was succeeded as president by Mr Ramaphosa.

He was jailed in 2021 for contempt of court after refusing to testify before a panel probing financial sleaze and cronyism under his presidency. His jailing sparked protests and riots that left more than 350 people dead.

He spent two months in prison before being released on medical grounds. That release was later ruled illegal, but he did not return to prison due to overcrowding in the system.

The ANC faces national elections next year viewed by many as the most competitive since it came to power in 1994.