Twenty-eight female guards were unfairly dismissed by a security company because the client‚ Metrora.
ANC supporters allegedly blocked a DA rally and tried to prevent its leader, Helen Zille, from addressing a meeting in Mpumalanga last week.
Zille's "state of the nation" tour turned ugly in Siyabuswa when a group wearing ANC T-shirts and holding Jacob Zuma placards chanted slogans and blocked the entrance of a local hall.
Zille accused the ANC of "mobilising supporters to disrupt opposition parties' meetings because the public was losing trust in the ruling party. It takes time for the public's trust to erode to the point where voters decide to do something about it. When that trust begins to erode, it reaches a tipping point.
"This election will be that tipping point. The ANC knows this. That is why it is mobilising its supporters to disrupt opposition meetings and intimidate voters," Zille said.
The DA leader had earlier pushed her way through a group barricading a community hall trying to prevent her addressing her supporters.
"We will not be intimidated by political thugs," she said.
Paul Mbenyane, the ANC's provincial spokesman, condemned the incident.