Pennsylvania Democratic Rep. Allyson Schwartz, a leader of the party's House campaign committee, called Wednesday for Rep. Anthony Weiner to resign after he admitted he sent lewd photos to women and talked dirty with them via Twitter and Facebook.
Weiner's behavior was so offensive he has lost the ability to command respect from his constituents and brought dishonor to the House, Schwartz said.
"As Americans we have the right to expect better behavior from members of Congresss, leaders of our country," Schwartz said in an interview. "I don't think we should accept it."
She was the first Democrat to say publicly that Weiner should step down, though others joined in later Wednesday, as the New York representative admitted through a spokesman that he was both the subject and sender of an X-rated picture of a man's genitals circulating on the Internet.
Separately, several media outlets reported that Weiner's wife - Huma Abedin, a top aide to Secretary of State Hillary Clinton - is pregnant with the couple's first child.
The statement from Schwartz, who is in charge of candidate recruitment and member services for the Democratic Congressional Campaign Committee, was interpreted as a strong signal that the party leadership wants Weiner out of the House - and out of the way.
But Schwartz said she did not talk to colleagues about the issue before making her statement. The House is not in session this week and Schwartz was away last week mourning the death of her father.
"I had a very individual, personal reaction," Schwartz said. "Maybe it's because I was hearing about it as other Americans were hearing it, unfiltered by conversations with colleagues."
Weiner, in his eighth term representing a district in Brooklyn and Queens, has made no comment since saying at a news conference on Monday that he would not resign.
At the news conference, Weiner admitted to sending a photo of his bulging underpants to a woman on Twitter - after claiming for nearly a week that his account on the social-media service had been hacked. That photo was unearthed and first reported by Andrew Breitbart, a prominent conservative blogger.
At the news conference, Weiner also said he exchanged messages and photos of an explicit nature with about six women over the last three years.
The Weiner controversy has dominated the news and deflected attention from the debate over the nation's debt limit, as well as Democrats' efforts to batter Republicans for proposing to privatize Medicare.
Democratic Leader Nancy Pelosi of California formally requested an ethics investigation to determine whether Weiner broke House rules. No Democrats have come to Weiner's defense publicly.
Tim Kaine, the former Democratic National Committee chairman who is running for the Senate in Virginia, also said Weiner should step aside.
"Lying is unforgivable," he told WCAV-TV in Charlottesville, Va., on Tuesday. "Lying publicly about something like this is unforgivable and he should resign."
Weiner, an aggressive spokesman for the liberal point of view on cable TV shows, has long harbored ambitions of being mayor of New York.
Former Pennsylvania Gov. Ed Rendell also said that Weiner should quit, and suggested that he get mental-health treatment.
"What I think Anthony Weiner should do is, he still has a lot to offer, he should resign, he should get treatment - and I mean real treament, maybe in-patient treatment," Rendell told Chris Matthews on MSNBC's Hardball Wednesday evening. "If he can rehabiliate himself, can he someday down the road in New York run for office? Maybe, maybe. But he's got to resign. He owes it to the party, he owes it to Congress, and he owes it to the issues he fought for."