Speaker Nancy Pelosi has announced a team of seven Democrats who will prosecute the impeachment case against Donald Trump.
Adam Schiff, the House Intelligence Committee chairman, 59, will lead the House "managers" who will put the case to senators that Mr Trump should be ousted for pressuring Ukraine to investigate political opponent Joe Biden and obstructing Congress.
Mr Schiff spearheaded the House impeachment investigation into Trump's dealings with Ukraine late last year.
The president called Mr Schiff, a former federal prosecutor, "a deranged human being" at a NATO meeting in December.
Jerry Nadler, the House Judiciary Committee chairman, 72, was also named as a member of the Democrats' team.
After weeks of delay, the House is expected on Wednesday afternoon to send impeachment charges against Mr Trump to the Senate, clearing the way for the trial to start next week.
The weeks-long trial is expected to ultimately end in the president's acquittal. But it will focus attention on Mr Trump's efforts to pressure Ukraine to investigate Mr Biden.
Mr Biden is one of 12 candidates vying for the Democratic nomination, and the trial might still be underway when Iowa and New Hampshire hold their first nominating contests in February.
None of the Senate's 53 Republicans have voiced support for ousting Mr Trump, a step that would require a two-thirds majority in the 100-member chamber.
