Cape Town – The ANC parliamentary caucus described the behaviour of one of its members, Mervyn Dirks, as "despicable" after he allegedly threatened to assault a female colleague.During the National Assembly's last plenary for the year on Thursday, Dirks allegedly insulted and threatened to assault ANC MP Thozama Mantashe. She is the younger sister of ANC secretary general Gwede Mantashe.Despite opposition MPs saying that they saw the altercation, house chairperson Cedric Frolick did not send him out of the chamber. He was later sent out for showing his middle finger. Dirks denied the allegations.READ: ANC MP Dirks alleged to have threatened female colleague during parliamentary sitting"The office of the ANC chief whip strongly condemns the incident," read a statement from the office of ANC chief whip Jackson Mthembu. "The behaviour of ANC MP Mervyn Dirks was despicable and not in keeping with the image of Parliament and the organisation he represents, the African National Congress. "Member Dirks further went on to show his middle finger to other members of Parliament. This member also allegedly called other members of Parliament dogs on his Facebook account." Mthembu has written to National Assembly Speaker Baleka Mbete to request an investigation."If found to be true, these actions cannot go unpunished. Disciplinary action"We have also written to the secretary general of the ANC to institute disciplinary action against this member. We believe that these actions amount to gross misconduct and bring the organisation into disrepute," read Mthembu's statement. "It is very regrettable that, while observing 16 Days of Activism Against Women and Child Abuse, a male member of Parliament would threaten to assault a female member in Parliament," Mthembu added, echoing the sentiments expressed by Minister of Defence and Military Veterans, Nosiviwe Mapisa-Nqakula, on Thursday evening during the sitting. "Members of Parliament ought to be the custodians of our Constitution and this democracy. It is therefore unacceptable that a member of Parliament can be found to be involved in such unbecoming behaviour," said Mthembu. Parliament confirmed that Mbete was investigating the matter.A suitable course of action"The Speaker is in the process of determining a suitable course of action. This could include referring the matter to an appropriate committee of Parliament for further investigation and decision," read a statement from Parliament's spokesperson, Moloto Mothapo. "The alleged threatening gestures fly in the face of the 16 Days of Activism, during which society is raising awareness about violence against women and children and calling on men, particularly, to challenge behaviour and norms that condone violence." He said MPs were expected to uphold the values of the Constitution. "It is to the Constitution that members pledge allegiance before starting their duties as parliamentarians. The founding values of the Constitution – such as human dignity, advancement of human rights and freedoms, non-racialism and non-sexism – find expression also in the Code of Ethical Conduct for members, which requires members to promote and support ethical conduct by their leadership and example."In this context, the alleged conduct of Mr Dirks is highly concerning and cannot be condoned." The ANC Women's League called on Mbete to expedite the investigation.'Abuse must be condemned'"Any form of abuse to women must be condemned and perpetrators must face the law. We also take into account and acknowledge the principles of innocent until proven guilty. The ANCWL is resolute in supporting the victims of violence and it will reiterate this position," a statement from ANCWL spokesperson Meokgo Matuba read."Abuse of any human being in any form is wrong and must be condemned and those found guilty of abuse must be punished. ANCWL encourages the victim and witnesses of abuse to all give reports to law enforcement agencies for the law to take its course. " Dirks is already before Parliament's powers and privileges committee. Earlier this year, he also showed a middle finger and, when asked about it, he denied doing it, even though his action had been clearly visible from the press gallery and on the broadcast. In February he called DA MP Phumzile van Damme a "straatmeid", a racist and sexist slur. Dirks was also one of the ANC MPs who boycotted the meeting chaired by former dissident ANC MP Makhosi Khoza when Public Service and Administration Minister Faith Muthambi was to be interrogated over allegations of impropriety. During Tuesday's sitting, he had heated exchanges with DA chief whip John Steenhuisen and his deputy Mike Waters when he unsuccessfully tried to derail the debate on state capture.Dirks was also one of the ANC MPs who complained about Mthembu allowing the state capture debate during a "press briefing", with only the Gupta-linked ANN7 in attendance.