The Oxford Union has "apologised unreservedly" to a blind student who was "violently" removed from a debate.
The union said it was sorry for the "distress and any reputation damage" to Ebenezer Azamati, who was "accosted" by security when he tried to return to a seat on 17 October.
Video footage showed staff appearing to grapple with Mr Azamati in the chamber.
The student said it has made him feel "very distressed and traumatised".
In a statement to the BBC, the debating society said it was in ongoing discussions with Mr Azamati "in order to pursue a solution agreeable to all parties, which addresses the structural issues raised".
But members critical of how the union has handled Mr Azamati's case have put forward a "motion of impeachment" against the society's president Brendan McGrath.
Harry Hatwell launched the motion on Tuesday after it was reported by that several committee members resigned.
In demanding justice for azamati, we support the impeachment of the @OxfordUnion president; Brendan McGrath to make him pay for his action. We need 150 signatures within the next 48 hours and we will be having a group walk to the union today and tomorrow from Boswell's by 5:30pm pic.twitter.com/N4VQTPfPux— Oxford Africa Society (@oxfordafrica) November 19, 2019
Mr Azamati was "forcibly and violently prevented from re-entering the union", when he was confronted by a security guard as he tried to return to his reserved seat in the chamber before a debate, according to the university's Africa Society.
The postgraduate student from Ghana, who is visually impaired, sat in another seat offered by another member before staff attempted to remove him.
Nwamaka Ogbonna, president of the Oxford University Africa Society, said the security guard had told Mr Azamati he could not enter the chamber because "the union was full".
Video footage shared online showed an argument between security and Mr Azamati in the chamber before staff appeared to manhandle him.
After the incident, a complaint against Mr Azamati for violent behaviour was made and the student was suspended from the union, the Africa Society said.
But the union's president Mr McGrath withdrew the charges at an appeal hearing on Saturday after some members held a protest on Friday.
Mr Azamati said he was "very pleased" that claims of "false violent disorder" were retracted by the union, but said the incident made him feel "unwelcome in the union, Oxford and even the country".
Helen Mountfield QC, who represents Mr Azamati, said there were ongoing talks with the union over what steps it can take to address the "failings" exposed by the case.
The Oxford Union has a tradition of hosting debates stretching back to 1823 and is independent of the university.