Impeachment investigators ask Trump chief of staff Mick Mulvaney to appear in Congress

House investigators have asked President Donald Trump's acting chief of staff to appear before the impeachment inquiry.

Congressional investigators sent a letter Tuesday to Mick Mulvaney, the acting White House chief of staff and director of the Office of Management and Budget, to appear Friday for a deposition.

Lawmakers are particularly interested in asking Mulvaney about his admission during an Oct. 17 news conference that the White House sought a quid pro quo arrangement with Ukraine, and that such agreements were commonplace.