Provincial speaker Shahid Esau has apologised for his "racist" threat to replace the "too many black women" staffers at the legislature with "boere" (white men).

This came after Cosatu on Monday joined the fray and threatened to report him to the SA Human Rights Commission and the Public Protector if he did not apologise before Tuesday.

Members of Cosatu-affiliated unions and other legislature staff signed a petition to express disgust at Esau's remarks during an earlier staff meeting.

It read: "We are deeply offended, insulted and outraged by the racist and condescending remarks by the Speaker when he said that: 'There are too many black women in this institution, especially in committee section, and I will go as far as Northern Cape and Limpopo to get boere to come and work here'."

Esau, a sheikh and leading member of the Democratic Alliance and the Muslim Judicial Council, also came under fire from the Independent Democrats, ANC and Congress of the People, demanding he apologise.

His office responded by saying that his use of the word boere was a synonym for Afrikaner and he did not mean to offend. The word was used during a discussion on employment equity in the first staff meeting and he has since had a follow-up meeting with staff to clear the air, a statement from Esau's office said.

"In the (second) staff meeting the Speaker apologised if he unintentionally offended anyone. Given South Africa's difficulty history, employment equity matters can easily cause offence and should be handled with the utmost sensitivity. If the Speaker has inadvertently offended anyone, he would like to offer his sincere apologies for this," his office said.

Cosatu provincial secretary Tony Ehrenreich said the National Education Health and Allied Workers' Union, which organised the legislature staff, was about to prepare for industrial action if Esau had failed to apologise.

Ehrenreich said: "The workers affected are Cosatu members and we will do all we can to defend their integrity as workers. Now that he has apologised, the DA must formulate a policy that can guide them (DA) to respect women in this province. We will insist on such a policy." He said Cosatu had wanted Esau suspended and to have the matter investigated.

Esau was appointed Speaker by the DA.

Leader of the DA and Premier Helen Zille's spokesperson, Robert Macdonald, said: "This is not for the premier to respond to. It is something for the legislature to deal with. It would be like the president being asked to investigate the Speaker of Parliament. The executive is separate from the legislature."

He said he could not respond to whether the DA could act against Esau and suggested that since Zille was not feeling well, DA spokesperson James Selfe or party provincial leader Theuns Botha be approached for comment.

Selfe said he had just returned from a trip abroad and in order to give an informed comment, would first have to acquaint himself with the issue.

Botha could not be reached.

ANC and opposition leader in the legislature Lynne Brown, who had earlier described Esau's behaviour as "shocking", said on Monday: "If he has apologised, then we must accept his apology. I hope that this has been a lesson for the Speaker. He must understand that transformation is not just about numbers."

ID provincial secretary Rodney Lentit said the matter should be a good lesson for Esau. "The ID welcomes the apology. It is the honourable thing to do. This is the way we know him and salute him for doing this. In the province race is a very sensitive matter and this should be a lesson to not only the Speaker, but other politicians."