A week ago, Lekota made a statement in the House calling for Zuma to be "impeached".

Among other things, he said Zuma's office had, on October 19, "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Court of Appeal, to hand over the abbreviated transcripts of the tapes that permitted criminal charges to be dropped or withdrawn against himself".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 said Zuma was bound by his oath of office to obey, respect and uphold the Constitution.

"As his office and his lawyers act daily under his direct authority, the inescapable conclusion is that the president is illegally refusing to be bound by... the Constitution, which binds all persons to obey a judicial order, and there are no exceptions," he said at the time.

On Tuesday, Deputy Speaker Nomaindia Mfeketo said Lekota should have brought his allegations to the Assembly by way of a substantive motion, and ruled his statements "unparliamentary".

She asked him to withdraw the statements. Lekota refused, saying the issue was sub-judice and he could not pre-empt a pending court ruling.

Following a number of ensuing points of order and repeated requests by Mfeketo for him to leave the chamber, he and most other Cope MPs eventually walked out.