Peers have overwhelmingly backed the suspension of Lord Maginnis from the House of Lords for at least 18 months for the bullying and harassment of three MPs and a security guard.
Members voted by 408 to 24, majority 384, to support the sanction recommended by the Lords Conduct Committee.
While the report’s findings would ordinarily have been rubberstamped, it went to a vote after calls from a number of peers.
Analysis of the division list showed 12 Tory peers voted against, including former Commons deputy speaker Lord Framlingham, ex-minister Baroness Buscombe and former MEP Lord Balfe.
The recommendation by the peers’ standards watchdog follows an investigation into Lord Maginnis’s treatment of a parliamentary security officer and MPs Hannah Bardell, Luke Pollard and Toby Perkins, during which he was found to have used homophobic slurs.
The committee suggested his 18-month suspension could be extended if he does not undergo training and change his ways.
Introducing the report, conduct committee chairman and former Supreme Court justice Lord Mance said the issue of concern was “not Lord Maginnis’s beliefs but his behaviour”.
“It is of paramount importance that all members of the parliamentary community of all backgrounds, sexual orientation and beliefs and of any status should feel safe and respected when they come here to work.
“Bullying and harassment, such as that demonstrated by Lord Maginnis, must be subject to significant sanction to safeguard all members of the parliamentary community, and evidence is then required that the perpetrator understands why their behaviour is wrong and how it must change before they can be allowed back into Parliament.”
Lord Maginnis, the ex-MP for Fermanagh and South Tyrone, was investigated after being “verbally abusive” to security officer Christian Bombolo when asked to show his parliamentary pass in January.
Mr Bombolo told Lords standards commissioner Lucy Scott-Moncrieff the incident had left him feeling “humiliated” and “worthless”, adding: “I lost my esteem, my dignity.”
According to the committee’s report, she complained that when she attempted to intervene in the clash between the peer and the security guard, she was treated “rudely and aggressively” by Lord Maginnis, who later used “homophobic and derogatory language about her” in comments to the media.
At the time, the Huffington Post said Lord Maginnis referred to Ms Bardell as “queer” and accused her of gaining “cheap publicity” by raising the incident as a point of order in the Commons.
The Metropolitan Police confirmed in January, after the clash was made public, that it was investigating an allegation of hate crime at the House of Commons.
Lord Maginnis was an Ulster Unionist Party MP but in 2012 announced his decision to resign his membership after the leadership distanced themselves when he referred to gay marriage as “unnatural and deviant behaviour” and linked it to bestiality.
Complaining about Mr Pollard’s conduct to chairman of the group James Gray MP, he sent an email with the subject heading “Discrimination by Homos”.
Shadow environment secretary Mr Pollard said in his complaint that he was “shocked and surprised that this type of behaviour would happen within Westminster” and said the email made him feel like a “victim of abuse”.
In the committee’s report, it said Lord Maginnis showed a lack of contrition.
Responding to questioning from the standards commissioner about the incident with Ms Bardell, the 82-year-old is said to have accused the MP of having a “serious mental illness and psychopathic disorder” and labelled the accusations a “lying tirade”.