The White House official who Bob Woodward charged had crossed a line by saying he would "regret" printing his version of a set of Washington negotiations was Gene Sperling, the director of the White House Economic Council, a source familiar with the exchange told BuzzFeed Wednesday.

The email from Sperling to Woodward, which Woodward read to Politico on Wednesday, has transfixed Washington, with Republicans and some in the press charging that it embodies a White House lording it over a cowed press corps.

Woodward, Politico reported, called the top official — identified to BuzzFeed as Sperling — to tell him that he would question Obama's account of negotiations leading to the "sequester" — automatic cuts set to take effect next month.

The aide "yelled at me for about a half hour," Woodward said, and then sent a follow-up email that read, in part: "You're focusing on a few specific trees that give a very wrong impression of the forest. But perhaps we will just not see eye to eye here. … I think you will regret staking out that claim."

Officials often threaten reporters that they will "regret" printing something that is untrue, but Woodward took the remark as a threat.

"They have to be willing to live in the world where they're challenged," he told Politico. "I've tangled with lots of these people. But suppose there's a young reporter who's only had a couple of years — or 10 years' — experience and the White House is sending him an email saying, 'You're going to regret this.' You know, tremble, tremble. I don't think it's the way to operate."

Sperling, a former aide to Clinton Treasury Secretary Robert Rubin who held the same position in Clinton's second term, is a veteran Democratic budget wonk and party insider. Remarked one friend Wednesday, he is "not exactly cut from the classic, no-drama Obama cloth."

Sperling didn't respond to an email inquiry about the exchange; a White House spokesman declined to comment on the authorship of the email to Woodward.