“It is essential that due process be respected and that all involved are given the opportunity to be heard,” Ms. Pelosi said in a statement Wednesday.

Mr. Ellison’s request comes about one month after his former girlfriend, an environmental political organizer named Karen Monahan, publicly accused him of emotional abuse and said he once tried to drag her off a bed while shouting profanities at her. She said initially that she had a cellphone video of the incident but has declined to share it, saying that victims should not be forced to prove their claims.

“Four people, including my supervisor at the time, stated that I came to them after and shared the exact story I shared publicly, I shared multiple text between me and Keith, where I discuss the abuse with him and much more,” Ms. Monahan tweeted recently. “As I said before, I knew I wouldn’t be believed.”

[A test for where to draw the line between a messy relationship and an emotionally abusive one]

Republicans, and some state Democrats, have seized on the allegations against Mr. Ellison, particularly as he attempts to win the Minnesota attorney general position this November. Mr. Ellison has said he has been cooperating with an independent inquiry into the matter, in addition to calling for the House Ethics Committee to investigate.

Still, the continuing questions may not deter Mr. Ellison from ascending to the attorney general post. In August, he won the Democratic primary by about 30 points just days after the allegations surfaced. Recent polling shows Mr. Ellison holds a lead — albeit a slim one — against his Republican opponent in November.