Public Enterprises Minister Pravin Gordhan says his detractors should appear before the judicial commission of inquiry into allegations of state capture and "say their piece under oath".
Gordhan, who is testifying at the commission for a second day, told inquiry chairperson Deputy Chief Justice Raymond Zondo that he was not "accountable to bullies".
"As far as I'm concerned, I'm accountable to citizens of this country, then Parliament and my political organisation, but I'm not accountable to bullies," he said.
"Those making allegations outside or inside this forum should, under oath, come to this commission and say what they have to say.
"They must subject themselves to cross-examination. I appeared before Nugent, under oath, and also here and have nothing to fear. I am not a commodity for sale, and the Guptas learned that too."
Gordhan was referring to the commission of inquiry, headed by retired Judge Robert Nugent, into operations at the South African Revenue Service.
He said Nene's removal had an impact on ordinary South Africans. He said at the time, the rand depreciated from R14.59 to the US dollar on the evening of December 9, to R15.90 on December 11.
"The decisions we make affect ordinary South Africans. The concern shown by different interest groups that weekend was therefore justified," he said.
While he was overseeing the Department of Cooperative Governance and Traditional Affairs, he was summoned to a meeting with Zuma.
He said ANC deputy secretary general Jessie Duarte and then deputy president Cyril Ramaphosa contacted him and told him that he would be asked to do something by the president and he should not refuse.
He said during his conversation with Zuma the former president indicated that he wanted him to take up the finance minister job and said: "I'm the one that can calm the markets."
He said he was asked to return to National Treasury even though Des van Rooyen, the MP appointed by Zuma in Nene's place, "seemed to be fine", according to the former president.
Gordhan also told the commission that there was no position for former finance minister Nhlanhla Nene at the Brics bank.
"There was no commensurate position to minister of finance for Nene at the Brics bank. I was involved in setting up the bank, I would know," he said.
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