The basics: Who, what, when and how to watch.
Who: Gordon D. Sondland, the ambassador to the European Union, will appear by himself in the morning session. Laura K. Cooper, a deputy assistant defense secretary, and David Hale, the under secretary of state for political affairs, will testify together in the afternoon session.
What: The House Intelligence Committee, led by its chairman, Representative Adam B. Schiff, Democrat of California, will continue to examine the case for impeaching President Trump. The Republican minority, led by Representative Devin Nunes of California, will again work to poke holes in testimony implicating the president.
When and Where: The morning proceedings start at 9 a.m. Eastern in the vaulted, columned chambers of the House Ways and Means Committee, and could last until the early afternoon. The second set of hearings is scheduled to start around 2:30 p.m., depending on when the morning session is finished.
How to Watch: The New York Times will stream the testimony live, and a team of reporters in Washington will provide real-time context and analysis of the events on Capitol Hill. Follow along at nytimes.com, starting a few minutes before 9.
Sondland kept Pompeo apprised of his efforts to get Ukraine to promise investigations Trump wanted.
Mr. Sondland, the diplomat at the center of the House impeachment inquiry who is to testify on Wednesday, kept Secretary of State Mike Pompeo apprised of his efforts to pressure Ukraine’s leaders to commit publicly to investigations Mr. Trump wanted, two people briefed on the matter said.
Mr. Sondland informed Mr. Pompeo in mid-August about a draft statement that Mr. Sondland and another American diplomat had worked on with the Ukrainians that they hoped would persuade Mr. Trump to grant Ukraine’s new president the one-on-one meeting he was seeking, the people said, speaking on the condition of anonymity because the discussions were intended to be private.
Later that month, Mr. Sondland discussed with Mr. Pompeo the possibility of arranging a face-to-face meeting in which President Volodymyr Zelensky of Ukraine would promise Mr. Trump that he would pursue investigations Mr. Trump sought.
Mr. Pompeo approved of the plan, which was meant to break a logjam in relations between the two countries, the people said, but the meeting between the two leaders never happened.
The disclosures tie Mr. Pompeo more directly than was previously known to the Trump administration’s pressure campaign on Ukraine.
Sondland will be pressed to explain conflicting accounts after other witnesses put him at the center of the case.
Mr. Sondland is expected to face tough questions on Wednesday about gaps and misleading statements in his initial closed-door interview with impeachment investigators on Oct. 17, an account that he has already been forced to revise once in response to other witness testimony.
After initially testifying that he “never” thought there was any precondition on $391 million in American security aid to Ukraine frozen by Mr. Trump, Mr. Sondland later submitted a three-page declaration saying “I do now recall” telling a senior Ukrainian official that “resumption of the U.S. aid would likely not occur until Ukraine provided the public anticorruption statement that we had been discussing for many weeks.”
The “anticorruption statement” would commit Ukraine to investigating Mr. Biden and the 2016 conspiracy theory involving Democrats, a statement that Ukrainian officials had resisted making.
In the statement, Mr. Sondland said that he did not know why Mr. Trump suspended the aid and that he “presumed” the connection after weeks went by without the money being released. Democrats will certainly press him about whether the president himself ever linked the aid to the investigations the way Mr. Sondland did in his Sept. 1 conversation with the Ukrainian official.
Mr. Sondland only offered this new account after William B. Taylor Jr., the top American diplomat in Ukraine, and Timothy Morrison, then the top Europe adviser at the National Security Council, told House investigators about it.
Before then, catch up on some important background on the impeachment inquiry.
Mr. Trump and his advisers repeatedly pressured Mr. Zelensky and his aides to investigate people and issues of political concern to Mr. Trump, including the former vice president. Here’s a timeline of events since January.
A C.I.A. officer who was once detailed to the White House filed a whistle-blower complaint on Mr. Trump’s interactions with Mr. Zelensky. Read the complaint.