Top diplomat testimony blocked by Trump administration -- less than an hour before impeachment committee meeting

The Trump administration on Tuesday ordered European Union ambassador Gordon Sondland not attend previously scheduled congressional hearings in which he was supposed to testify about his role in getting the Ukrainian government on board with investigating former Vice President Joe Biden.

The New York Times reports that the decision to block Sondland's testimony came less than an hour before he was scheduled to deliver congressional testimony. According to the Times, the Trump administration "appears to be making the calculation that it is better off risking the House’s ire than letting Mr. Sondland show up and set a precedent for cooperation with an inquiry they have strenuously argued is illegitimate."

House Democrats, however, have vowed that any effort to block administration officials from testimony will be viewed as obstruction of justice and will be added to eventual articles of impeachment against the president.

Sondland has emerged as a key figure into President Donald Trump's efforts to push the Ukrainian government to investigate his political opponents. In explosive text messages released last week, Sondland suggested that the Ukrainian government needed to agree to assist the president's investigations in order to secure a face-to-face meeting between Trump and Ukrainian President Volodymyr Zelensky.

In one particularly damning text message exchange, veteran diplomat Bill Taylor told Sondland that it was “crazy” to tie Ukrainian military assistance to the country helping the president’s electoral prospects. Sondland then sent back a text message denying any quid pro quo — and then urging Taylor to take the discussion offline.