South Africa's former finance minister Pravin Gordhan, whose sacking has fuelled divisions within the ANC party, warned Thursday that the government risked being taken over by "a bunch of gangsters".
President Jacob Zuma sacked Gordhan last week in a cabinet overhaul that threatens to split the ANC party, which has been in power since the end of apartheid in 1994.
Gordhan, widely respected by many South Africans and financial investors, made no direct mention of Zuma in his speech and pledged his loyalty to the ANC.
"We are running the risk in South Africa that honest people don't want to participate in government institutions," Gordhan said.
"When the society reaches that point, then we know that we have handed over the state to a bunch of gangsters."
Gordhan, who was seen as a bulwark against corruption, also warned of "the abuse of state institutions for the wrong purposes."
"Instead of chasing criminals we have many agencies chasing up and trying to criminalise honest people," he said, speaking in Cape Town at a memorial service for anti-apartheid stalwart Ahmed Kathrada.
The axing of Gordhan and his deputy Mcebisi Jonas saw Standard and Poor's cut South Africa's sovereign credit rating to below investment-grade, sending the local rand currency tumbling.
The reshuffle also strengthened calls for Zuma to resign, with several senior ANC figures criticising Gordhan's removal.
Gordhan's speech was greeted with loud cheers in the packed cathedral, with some people holding up posters saying: "Zuma must go".
On Friday opposition parties and civil groups plan to hold anti-Zuma demonstrations in the capital Pretoria, and Johannesburg.
Parliament will vote on a motion of no confidence in the president on April 18, though he has easily survived previous such votes against him.
Since coming to power in 2009, Zuma has been hit by a series of corruption scandals.
The president has been accused of being in the sway of the wealthy Gupta business family, allegedly granting them influence over government appointments, contracts and state-owned businesses.