Lt. Col. Alexander Vindman, the top Ukraine specialist on the National Security Council. Vindman listened to the July 25 telephone conversation in the White House Situation Room and reported his concerns about the president's mention of political investigations to the top NSC attorney, John Eisenberg. He said the attorney decided to move the record of the call onto a highly classified system that few could access.
Jennifer Williams, a foreign service aide detailed to Vice President Pence's office who listened in on the July 25 call between Trump and Zelenskiy.
Tuesday, second panel at 7:30 p.m. GMT
Kurt Volker, the former special envoy to Ukraine, who along with Sondland and Energy Secretary Rick Perry was part of the "three amigos" tasked by the president to handle Ukraine policy. He was on the list of witnesses requested to appear by Republican members of the Intelligence Committee.
Tim Morrison, the former National Security Council aide who heard the July 25 call but in closed-door testimony told the committees conducting the impeachment inquiry that he didn't view the president's actions as illegal or inappropriate. Republicans say his testimony supports the president's position that there was nothing improper about the July 25 call, and they included him on a list of witnesses they asked the Intelligence Committee chairman, Rep. Adam Schiff, D-Calif., to call.
New witness for Thursday -
WASHINGTON (Reuters) - David Holmes, a U.S. embassy official in Ukraine, will testify publicly on Thursday before the U.S. House of Representatives Intelligence Committee in the inquiry into whether President Donald Trump should be impeached, the panel said on Monday.
Holmes told lawmakers in a closed-door deposition on Saturday that he overheard a phone call between Trump and Gordon Sondland, the U.S. ambassador to the European Union, in which the president inquired about Ukraine’s willingness to carry out investigations of former Vice President Joe Biden and his son.