The equality court in Cape Town wants DA chief whip John Steenhuisen to give evidence in a matter in which one of his MPs, Dianne Kohler Barnard, is accused of making racist, sexist and xenophobic statements.

Cape Town chief magistrate Daniel Thulare ruled on Friday that the court will inquire into a complaint by Louw Nel, the party's former director of parliamentary operations who accuses Kohler Barnard of making "discriminatory utterances" during a workshop attended by DA staff members in parliament. The workshop was held to discuss safety and security strategy last February.

Kohler Barnard does not deny making the statements, but argues in her responding affidavit that Nel omitted the context in which her comments were made - that she merely relayed information gathered during a work-related trip and that her comments did not constitute unfair discrimination.

She also claims that Nel misquoted her actual utterances and in some instances his accusations were simply contrived.

Thulare instructed the clerk of the court to issue subpoenas to Steenhuisen, DA MP Zak Mbhele and two former staff members to appear before the court next month. Thulare also instructed that the station commissioner of the Cape Town police ensure they submit affidavits in two weeks' time in relation to Nel's complaint.

Nel, who is representing himself in the case, requested the assistance of the court in getting the four men to give evidence. He revealed that the two former staff members – Grant Caswell and Kabelo Mhlohlo - had been reluctant to submit affidavits as corroborating witnesses due to concerns about the consequences doing so might have on their jobs.

"They are currently not employed by the DA but they are employed by DA-led governments, and they are concerned about repercussions of them providing affidavits. They have both made it clear that they would cooperate with the courts," Nel told the court.

Nel wanted the court to call Steenhuisen because "he is the individual to whom I escalated this matter and according to press reports, he says he issued the respondent [Kohler Barnard] with a reprimand".

"It's important to hear the chief whip about the version of events she presented to him at the time. It's important to learn what was she reprimanded for. One can't reprimand a person if they had done nothing wrong,” he said.

Thulare indicated that in the course of inquiring into the matter, he may call other witnesses including Kohler Barnard herself to take the stand.

"Even if you advise Ms Kohler Barnard not to be a witness, nothing precludes me in the process of my inquiry to call her, to want to hear her before I make a determination," Thulare said.

Kohler Barnard's lawyer, Michaela Tsele, tried to convince Thulare that Nel's complaint had no basis in law.

He said even if the court were to admit Nel's allegations as the true reflection of what his client had said, they would not amount to unfair discrimination as per the Promotion of Equality and Prevention of Unfair Discrimination Act [Pepuda].

"On any conceivable interpretation of those words, whether Nel's or the court's interpretation, they do not amount to an offence or unfair discrimination," he said.

"Even if you accept what he states as is in the founding affidavit, that does not constitute unfair discrimination as defined by Pepuda - that is a point of law more than anything else.

"I would suggest a better way of managing the proceedings is to say 'well if that's the case, should the court not hear submissions on that legal point and determine whether the founding papers as they stand constitute an offence alleged as unfair discrimination?'. If it is accepted, would that be a basis for a finding of guilt as the affidavit stands?” Tsele asked.

Thulare disagreed saying the court would have to come to its conclusions about what Kohler Barnard had meant with her words before finding whether they were a breach or not of the law.

The matter has been set down to hear oral evidence for five days starting on June 10.