The nation's top intelligence official is expected to face fierce interrogation from lawmakers on Thursday morning over his decision to withhold a whistleblower's complaint about a phone call between President Trump and Ukraine's leader that has prompted congressional Democrats to open a formal impeachment inquiry.

>>WATCH A LIVE STREAM OF THE HEARING HERE.

Joseph Maguire, the acting director of national intelligence, will be testifying before the Democratic-led House Intelligence Committee to discuss the complaint, which was provided to certain lawmakers on Wednesday afternoon.

His appearance on Capitol Hill is the latest flash point in an extraordinary series of events over the past two weeks which have precipitated a constitutional clash between the White House and the Democratic-controlled House.

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