The DA is threatening legal action against speaker of the Mpumalanga legislature Yvonne Phosa, who is also the wife of ANC treasurer general Mathews Phosa.
The threat follows the expulsion of Mpumalanga DA leader Anthony Benadie from the legislature yesterday.
Benadie had refused to apologise - as demanded by Phosa - after he had raised a point of order during Premier Thabang Makwetla's response during debate on the state of the province address.
Benadie raised a point of order after Makwetla made "an incorrect reference" from the speech he [Makwetla] had delivered.
ANC chief whip Jackson Mthembu then introduced a motion without notice, demanding that Benadie apologise to the house and the premier.
The ANC supported the motion while the DA opposed it.
Phosa then refused to take a point of order from DA chief whip Clive Hatch who argued that in terms of rule 82(6) any motion introduced without notice requires unanimous approval by members.
After the third attempt to raise the point of order Hatch left the house in protest.
While Benadie referred to the hospital manager of the Middelburg Hospital, Makwetla referred to the hospital chief executive and medical manager.
In his objection Benadie pointed out that Makwetla was misrepresenting the facts.
Benadie has described the move as "absolutely absurd".
"We are investigating the possibility of taking legal action against the speaker for disregarding the rules of the house and violating the individual rights of DA members," he said.
In her ruling, Phosa created a perception that Benadie and Makwetla were talking about different issues and thus Benadie's point was not sustained.
Benadie said that it was his democratic right to raise points of order in terms of the legislature rules.
Benadie requested Phosa to explain what rules he had contravened and why he had to apologise.