One of the key witnesses who testified at the impeachment investigation of President Trump has been fired from his job at the White House and escorted by security out of the building.
Lieutenant Colonel Alexander Vindman told Congress that he was surprised and alarmed when he heard President Trump pressure the Ukrainian leader to dig up dirt on former Vice President Joe Biden, the man who hopes to be the Democrats' candidate in this November's US election.
Our Washington Correspondent Simon Marks reports.
IN: "Alexander Vindman…"
OUT: "…on this President"
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