Michigan representative John Conyers Jr. steps aside as ranking Democrat on the House Judiciary Committee.
Conyers says he is stepping aside pending an investigation into allegations of sexual harassment.
The ethics committee opened an investigation into Conyers after BuzzFeed News reported last week that he settled a wrongful dismissal complaint in 2015 with a former employee who alleged she was fired because she would not "succumb to his sexual advances."
Conyers, the longest serving current member of the house, has said he will "fully cooperate" with the ethics committee's investigation.
His announcement came after several democratic lawmakers called for him to step down from his powerful post.