Former finance minister Pravin Gordhan has denounced the behaviour of a large crowd of people who interrupted him and threw sewage outside a venue in KwaDukuza, north of Durban, where he was supposed to deliver a speech on Sunday.
Gordhan described their conduct as "intolerant" and said all organisations must condemn it.
The people, believed to be ANC Youth League members, prevented him from speaking at the Siva Sungum Hall, where a fundraising event for the Concerned Citizens Group (CCG) was held on Sunday.
The ANCYL has dismissed claims that it was involved.
Gordhan released a statement in which he voiced his opinion of the events that unfolded.
"Clearly, it appears that some people related to the issue or the current political events unfolding in the country, had organised a group of young people to violently disrupt this event," Gordhan said in the statement.
He said the Constitution provided for freedom of speech.
"The members of the community, who were present to express their support for the issues raised by the Concerned Citizens Group, had every right to safety and a peaceful event."
Organiser for the event and chairperson of the CCG Haroon Mohammedy said Gordhan was meant to speak on civic participation.
"There is a misconception he was coming to lend his support to our opposition at building a new mall in Stanger. We didn't give him a topic. We told him to speak to the audience about civic affairs and getting involved."
The CCG has opposed the building of a new mall in the town developed by Durban tycoon and ANC backer Vivian Reddy.
Gordhan said the intolerance displayed on Sunday "is what we experienced in the 1980s in particular".
The violence, physical attacks on people, the stealing of food prepared for the evening cannot be the conduct we either expect or condone – in the lead-up to decisive meetings later in December. I condemn this intimidation.
He said the violent and intolerant conduct must be condemned by all democratic organisations.
"This kind of intolerance will only serve to alienate more of the public."
Mohammedy said the CCG had seen people in the crowd wearing ANC T-shirts that displayed the face of presidential hopeful Nkosazana Dlamini-Zuma.
He said he too was interrupted by the crowd.
"They tried to disrupt me when I was speaking by attempting to gain entry into the hall. This didn't happen."
But he said the crowd became even more unruly when Gordhan began to speak.
"His security team agreed they needed to leave. He was meant to leave early anyway because of his flights. But he was cut short."
ANCYL regional secretary Musa Zondi told News24 that it was disingenuous for anyone to accuse them of interrupting the event.
How do we know they are ANCYL? The regalia is available to all. We did not have any programmes on the day.
He labelled the CCG as "opportunist".
"The people in the CCG are business people who are opposed to a mall that will threaten their businesses. They are not for the interest of the people. We are for the people."