STORY: South Africa's top court has ruled that former president Jacob Zuma is not eligible to run for parliament in this month's election.

This was a closely watched decision because of its potential to influence the outcome of the vote.

Zuma, who was forced to quit as president in 2018, has fallen out with the governing African National Congress.

Instead he's been campaigning for uMkhonto we Sizwe, a new party named after the ANC's former armed wing.

Opinion polls suggest the ANC's majority is at risk for the first time in three decades.

And MK, as its known, is a threat - especially in Zuma's home province of KwaZulu-Natal.

Sihle Ngubane is MK's secretary-general.

"Jacob Zuma is still a party leader, Jacob Zuma is on the ballot paper of MK Party, and then people are still going to vote Jacob Zuma in numbers, and Jacob Zuma is the party leader of MK Party, he will give down direction from here onwards on what to do as MK Party."

Monday's ruling stems from a decision by South Africa's electoral commission in March to disqualify Zuma.

"I was lambasted with a punitive jail sentence..."

That was on the basis that the constitution prohibits anyone given a prison sentence of 12 months or longer from holding a parliamentary seat.

Zuma was sentenced to 15 months in 2021 for failing to appear at a corruption inquiry.

The jailing triggered riots in KwaZulu-Natal in which more than 300 people died and which morphed into a wider spate of looting.

In April a court overturned the disqualification, saying the relevant section of the constitution only applied to people who had had a chance to appeal their sentences, which had not been the case with Zuma.

The electoral commission then challenged that decision at the constitutional court resulting in Monday's ruling.