The event on Tuesday was late starting because of what organisers call "inadequate arrangements" for disabled people gaining access to the sprawling Parliament.
Aaron Israelson, one of the organisers, told this website, "We notified the Parliament that we'd be bringing in some people with disabilities, including seven people in wheelchairs and a blind person, but we encountered an awful lot of problems.
"It took over 40 minutes just to open the gates to get the participants inside the building, which I find quite unacceptably long.
"We'd asked if there would be any problems and were told there would be none."
Israelson, a communications assistant to Swedish S&D group MEP Soraya Post, who hosted the event, added, "The Parliament clearly has an infrastructure problem when it comes to disability access to the building. Basically, access for people with a handicap is not what it should be.
"This is rather ironic, given that the Parliament is supposed to be a beacon of democracy for all, including the disable, and that it likes to promote disability rights."
The event highlighted the plight of disabled people who are subject to domestic violence.
Soraya Post said the issue affected men, women and children with disabilities and had remained "under the radar of lawmakers for too long."
She said, "There is a chronic lack of awareness of this issue and that is something we need to address."
Her comments were shared by Ann Johsson, who represents the European Blind Union and is herself blind.
She said domestic violence can be physical, emotional and psychological and cited examples of the abuse suffered by some disabled people, including a husband who refused to provide interpretation for his deaf wife.
Meanwhile, the European Disability Forum (EDF), AGE Platform Europe and ANEC have said they are "deeply concerned" about the draft report by Parliament's internal market and consumer protection committee on the European accessibility act, published on 6 January.
A statement read, "The report is watering down the European Commission's proposal and we believe it threatens to lead to an unambitious position of the European Parliament which will not represent the interests of EU consumers, nor promote their rights effectively, including 80 million persons with disabilities and 190 million citizens aged 50 and older."
The organisations have written to MEPs "to draw their attention to several key elements of the report which threaten to adversely affect the scope, the accessibility requirements and mechanisms persons with disabilities can use to complain."