"Members of opposition in legislatures, in particular, are obliged to hold the president accountable in ensuring that he respect and safeguard his oath of office and provisions of the Constitution," Lekota said in a statement.

"My call for impeachment of the president has to do with the fact that the [he] has failed to lead the executive to fulfil the ruling of the judiciary."

Lekota told MPs on Tuesday that the president's office had, on Friday, "defied an order, by the Supreme Court of Appeal, to hand over the abbreviated transcripts of the tapes that permitted criminal charges to be dropped or withdrawn against himself".

He was referring to the refusal to release transcripts of the secret recordings which were the basis of the decision to drop corruption, fraud and racketeering charges against Zuma in early 2009.

Lekota called for impeachment procedures to be instituted against Zuma for his defying a lawful judicial order.

African National Congress spokesman Jackson Mthembu called Lekota's call "disingenuous".

"His statement is consistent with his personal hatred for President Zuma," ANC spokesman Jackson Mthembu said in a statement.

Mthembu called the Congress of the People an anti-Zuma party with no political programme.

Lekota said his call for impeachment was made in the political arena.

"[It is] not romance, even if it is spring-time," he said.

If Zuma was inclined to champion the Constitution, he would have instructed his lawyer to obey the judicial order.

"If there was no wrongdoing on his part there can be no criminal charges against him," said Lekota.

"The suspicion is now mounting that the tapes do not exist and the 300 criminal charges should, therefore, stand."