Wednesday's national shutdown by the ANC's alliance partners is the symptom of widening rifts within the once mighty tripartite alliance, a separation of ideology that may mark the beginning of the end for the almost 30-year pact.
In 15 cities throughout the country, Cosatu and its affiliate organisations, as well as the SA Communist Party (SACP), have banded thousands together in protests against state capture and corruption.
Their banners and their chants were also centred on calls for President Jacob Zuma's head to roll.
Politics expert Keith Gottschalk said Wednesday's national strike is a warning to the ANC.
"This is several years in the making. The SACP and Cosatu have previously protested state capture and corruption and, if it continues, there may be much larger consequences for the alliance in the future," Gottschalk said.
He emphasised that the fate of the alliance rests on the ANC's national conference in December where it will elect its new leadership.
"If an anti-corrupt candidate wins, it may strengthen the alliance. But if a pro-Zuma candidate is successful, the alliance may well be suspended for a few years."
Political analyst Prince Mashele said the marches "amplify" cracks in the alliance.
"You would not normally expect components of an alliance to go to the streets to send a message to a partner. This tells us that cracks are so wide that they may be impossible to repair," Mashele said.
"When you have the head of the alliance [the ANC] falling apart, other components are bound to fall apart. It has been a long time coming."
Cosatu and its affiliated unions have thrown their weight behind Deputy President Cyril Ramaphosa to become the ANC's next president.
The SACP has also decided to contest future elections -– although it did not say which elections -– independently from the ANC.
"If the vote doesn't go their way, it will be the end of the alliance. There is no way they will rally behind Nkosazana Dlamini-Zuma," Mashele said.
Wednesday's chants echoed those who heckled and booed Zuma and his staunchest of supporters at Worker's Day rallies in May.
Zuma, who was deemed the "workers' champion" in the run-up to his election, and who was carried to victory by the same alliance members now protesting against him, was chased away and stopped from addressing the crowd on that fateful day.
Years ago, SACP boss Blade Nzimande and Cosatu's then leader, Zwelinzima Vavi, and their hangers-on danced and jived on a stage outside the Pietermaritzburg High Court, shouting that the "head of the snake" (former president Thabo Mbeki) needed to be chopped off, while Zuma supporters burned T-shirts with Mbeki's face on it.
"All of these people knew they were backing a weak candidate [Zuma], but they thought they could control him. But, others outside the party had the same agenda and they won control instead," Mashele said.
"Now they are doing the same with backing Ramaphosa. They are jockeys trying to control a horse when they are not sure which way it will go."