Johannesburg - Finance Minister Pravin Gordhan and President Jacob Zuma appear to be embroiled in a "Mexican Standoff", the Democratic Alliance said on Friday.
Business Day reported that Gordhan had told Zuma shortly before his Budget speech that he would resign if he did not remove Sars commissioner Tom Moyane, as he could not work with him.
"The Minister of Finance Pravin Gordhan, should make a public statement clarifying his position on what appears to be a 'Mexican Standoff' between himself and President Zuma over the South African Revenue Service (Sars)," DA MP and finance spokesperson David Maynier said in a statement.
Gordhan should say whether he had given Zuma an ultimatum, and explain how he intended to deal with problems at Sars, Maynier said.
"The stakes are high and the minister’s resignation would be a disaster, sending us hurtling towards a sovereign ratings downgrade in South Africa," he said.
In December last year, Zuma replaced respected finance minister Nhlanhla Nene with ANC backbencher David van Rooyen. Following a public outcry, Zuma replaced Van Rooyen with Gordhan and made Van Rooyen co-operative governance minister.
Since then, insiders say that ANC leaders had given Gordhan a mandate to do whatever needed to be done to prevent South Africa from being downgraded to junk status.
On Monday, Zuma told reporters that Van Rooyen was the most qualified finance minister he had ever appointed, prompting speculation of tension between Zuma and Gordhan.
ANC secretary general Gwede Mantashe on Friday expressed the ruling party's support for Gordhan.
The ANC was "extremely concerned" about reports that the Hawks had sent questions to Gordhan four days before his Budget, regarding a rogue unit at Sars, Mantashe said in a statement.
"The timing of these questions indicates clearly that there was intention to distract the minister during this important time.
"It is even more disconcerting that these questions were leaked to the media. In our view, this is a well-calculated destabilisation plan with all the elements of disinformation, falsehoods and exaggerated facts," said Mantashe.
He commended Gordhan for his work and said it was unfortunate that there were efforts to undermine him and reverse the country's economic progress.