US Congresswoman Alexandria Ocasio-Cortez has given a speech rejecting a colleague's apology after he allegedly used a sexist slur in an argument.
The New York City Democrat took to the House floor to accuse Republican Ted Yoho of accosting her on the steps of the US Capitol.
Ms Ocasio-Cortez, who is often a target of conservatives, said the words showed a "pattern" of bad behaviour by men.
Mr Yoho denies saying the slur and has called for civility.
"This issue is not about one incident. It is cultural," she told lawmakers, calling it a culture "of accepting a violence and violent language against women, an entire structure of power that supports that."
She added that she was prepared to let the incident go until Mr Yoho "made excuses" by citing his wife and daughters in a speech on Wednesday.
Ms Ocasio-Cortez said she was entering Congress to vote when Mr Yoho, a Florida congressman, and Texas Congressman Roger Williams approached her as they departed the chamber.
She said he called her "disgusting" and said "you are out of your freaking mind" in what a reporter who also witnessed the incident called a "brief but heated exchange" about recent comments Ms Ocasio-Cortez made about crime being linked to poverty.
Ms Ocasio-Cortez - a member of the so-called "squad" of young female Democrats - said she told him he was being "rude".
Then, as Mr Yoho walked away, he was overheard by reporters using profanity and a sexist slur used to denigrate women.
Mr Yoho's office denies he used the sexist word, and said he had exclaimed "bullshit" to himself instead as he was leaving.