Army Lieutenant Colonel Alex Vindman testified in a televised House impeachment hearing over whether President Trump withheld military aid from Ukraine to pressure the Ukrainian president to investigate Trump’s political rival Joe Biden and his son. Among Vindman’s statements, he said he couldn’t believe what he was hearing when he listened to the July 25 phone call between President Trump and Ukrainian President Volodymyr Zelensky. During the call, Trump pressured Zelensky to investigate his political rival Joe Biden and his son Hunter, who served on the board of a Ukrainian natural gas company, Burisma. Vindman, who is the director for European affairs at the National Security Council, testified along with Jennifer Williams, a Russia adviser for Vice President Pence. On Tuesday afternoon, House investigators heard the testimonies of Kurt Volker, the former U.S. special envoy to Ukraine, and Tim Morrison, former senior director for European and Russian affairs on the National Security Council.

Today, U.S. Ambassador to the European Union Gordon Sondland will testify to lawmakers. Sondland is a wealthy hotel magnate and real estate developer in Oregon. He received his ambassadorship after donating a million dollars to Trump’s inauguration. His lack of diplomatic experience led one White House foreign policy adviser to complain Sondland was a national security risk.