Rep. Weiner is scheduled to speak at 4:00 PM ET. Live video at the top of this live blog.

At the Weiner presser, Breitbart takes to the microphone to defend his site's reporting.

"I'm not going to get into how Weiner should respond to this," he says. "I'm here to respond to some basic questions."

"We didn't name the girl," he says, but other sites "attacked the messenger."

"How is this revenge? There was zero premeditation involved in this. This is a legitimate story."

"I'm doing this to save his family" Breitbart says about his decision not to post a photo that the BigGovernment.com site describes as "extremely graphic, and leaves nothing to the imagination."

"I would like an apology from him... This was his political strategy -- to accuse me of hacking," Breitbart says.

"I'm trying to do the decent thing here and not release the photo."

"When I'm the one being accused, I have the right to speculate," Breitbart says.

"He's the one who has more questions to answer than I do," he concludes -- and indeed we're all waiting for him to take the stage.

Breitbart on the phone with Fox News: "I did so at their invitation. I did not do so as a means to crash. In fact when I was walking up there I asked whether this was a good thing to do."

Breitbart to Fox News, on his motivation for publishing the Weiner photos "I think that these guys are putting the country in harms way -- just like Congressman Lee or Congressman Weiner -- I believe that when you are sending these photos out to people across America, you are putting yourself in a blackmail position."

"I have made terrible mistakes that have hurt the people I care for the most."

"The picture was of me, and I sent it"

Weiner said that over the past several years he has engaged in inappropriate conversations online and over the phone with about six women. "I have never met any of these women or had physical relations with them at any time."

"I am not resigning," Weiner said. "It was a very dumb thing to do, but it was not part of any plan to be deceitful."

"This is not something that can be treated away. It is a deep weakness of mine, and it is a mistake."

"My wife has known about some of these online relationships since before we were married. But she did not know until this morning that I had not been truthful about the twitter posting last week."

He says he and his wife are staying together.

"I apologize to Andrew Breitbart, I apologize to the members of the media, and I apologize first and foremost to my wife."

Weiner's pointed humor makes a brief appearance when a reporter asks where his wife is:

"She is not here."

To to question of whether he had ever paid for escorts or engaged in other such behavior: "I have never had sex outside my marriage."

ABC News has released an interview with Meagan Broussard, a 26-year-old single mother from Texas who provided ABC with dozens of photos, emails, Facebook messages and cell phone call logs.

During one flirtatious Facebook chat last month, Broussard said, she issued the man on the other end a challenge.

"I asked him to take a picture and write 'me' on it so I would know," Broussard said in an interview.

The reply, she says, came moments later. Email records provided to ABC News by Broussard show that at 3:08 p.m. on May 5th she received a message from anthonyweiner@aol.com, which is listed as an email address for Weiner on one campaign document found online.

The message included an image of a man, who appears to be Weiner, sporting a tie and a wedding band, holding up the message "me" on a piece of white paper.

"I didn't think it was him," she says. "I thought for sure, 'why would someone in that position be doing this?'"

She says the online relationship started on April 20, 2011.

Read more here.

Weiner: "I lied because I was embarrassed. ... But did I violate the Constitution because I lied about a Twitter post? I don't think so."

The Washington Post's Chris Cillizza reports:

Weiner’s 9th district, which takes in parts of Brooklyn and Queens, is surprisingly competitive between the parties although any Democrat would likely be favored in any special election or open seat scenario.

The Wall Street Journal notes:

Earlier this year, Rep. Chris Lee, a married Republican from New York, resigned within hours after it was revealed he had sent a topless photograph of himself to a woman he met on Craigslist.

Should Weiner do the same?

CBS News producer Jill Jackson tweets:

@ jacksonjk : Leader Pelosi calling for ethics investigation into Rep. Weiner's actions.

More from Jackson:

Pelosi wants ethics investigation "to determine whether any official resources were used or any other violation of House rules occurred."

Pelosi: "I am deeply disappointed and saddened about this situation; for Anthony's wife, Huma, his family, his staff and his constituents. "