South Africa’s former President Jacob Zuma has been expelled from the African National Congress (ANC), the party he once led, after campaigning for a rival party in the 29 May general election.

The ANC’s disciplinary committee found Mr Zuma guilty of “prejudicing the integrity” of the party by joining uMkhonto we Sizwe (MK), and has given him three weeks to appeal against its ruling.

“His platform is dangerous, appeals to extremist instincts in our body politic and riles up a political base that may foment social unrest,” the ANC said in a statement.

MK has said that Mr Zuma was not informed of the decision taken by a “kangaroo court”.

Mr Zuma, 82, was an ANC veteran but fell out with the party after he was forced to quit as president in 2018 over corruption scandals. He has always denied any wrongdoing.

He had been suspended by the ANC in January after creating MK, which now sits in opposition to the ANC-led government in parliament.

In a statement, MK said it was shocked to learn from media reports that Mr Zuma had been expelled.

The disciplinary proceedings were conducted “in a manner akin to a kangaroo court”, the party said.

“It is a foundational legal principle that no person, not even those accused of a serious crime, should be punished or sentenced in their absence,” it added.

The ANC’s disciplinary committee held a virtual hearing, which Mr Zuma refused to attend, saying he wanted to be physically present.

At a press conference confirming Mr Zuma’s expulsion, ANC secretary-general Fikile Mbalula said the party had refused to agree to Mr Zuma’s presence at the party’s headquarters as he “wanted a rally”.

“Even when they [MK supporters] were told that the disciplinary hearing was virtual they still came here. So it tells you that Jacob Zuma wanted a movie,” he added.

Mr Mbalula denied that Mr Zuma had not been informed of his expulsion.

“[The] kangaroo court is that MK. Who are they to lecture people about a due process?,” Mr Mbalula said.

He added that the ANC did not think that at any point in its history it would have to deal with a former president “campaigning decisively against the party he was a member of”.

South Africa’s current President Cyril Ramaphosa replaced Mr Zuma in 2018, promising to clean up government.

But in the 29 May elections, the ANC suffered its worst result in 30 years, pushing the ruling party to form a coalition to share power.

uMkhonto we Sizwe – meaning “spear of the nation” – became the country’s third-largest party, largely by taking votes from the ANC.

It won almost 15% of the vote and obtained 58 seats in the 400-member parliament.

MK became the official opposition in parliament after the second-biggest party, the Democratic Alliance (DA), joined the coalition government.

Mr Zuma was barred from being an MP because he was given a 15-month prison sentence in 2021 for contempt of court. He defied a court order to appear before an inquiry investigating corruption during his nine-year presidency.

His arrest sparked the deadliest riots since the end of white-minority rule in 1994 and led to the deaths of more than 300 people.

And he now faces corruption charges over a 1999 arms deal.

He has chosen an ex-judge, who was impeached for gross misconduct, to lead MK in parliament.