The hearing will hear testimony on the impeachment process established under the US Constitution from a panel of legal experts that has yet to be named
US President Donald Trump faced two deadlines in Congress on Sunday as Democrats prepared to shift the focus of their impeachment inquiry from fact-finding to the consideration of possible charges of misconduct over his dealings with Ukraine.
The Democratic-led House of Representatives Judiciary Committee, tasked with considering charges known as articles of impeachment, has given the president until 2300 GMT on Sunday to say whether he or his legal counsel will participate in an impeachment hearing on Wednesday.
The hearing, the first in a series of proceedings expected before the committee, will hear testimony on the impeachment process established under the US Constitution from a panel of legal experts that has yet to be named.
Hearings before the committee, which has responsibility for crafting any formal charges against Trump, are a major step toward possible charges. Democratic House Speaker Nancy Pelosi, who will make the final decision, has not said yet whether the Republican president should be formally impeached. But in a letter to supporters last week, she called for him to be held accountable for his actions.
Trump has denied any wrongdoing and called the impeachment inquiry a witch hunt aimed at unseating a democratically elected president. The White House has not yet indicated whether it will take part in the House Judiciary proceedings.
House Judiciary Chairman Jerrold Nadler has also set 2200 GMT deadline on Friday for Trump to say whether he intends to mount a defence at further proceedings expected next week that would examine the evidence against him.
Three investigating panels, led by the House Intelligence Committee, are due to release a formal evidence report this week after lawmakers return to Congress on Tuesday from their Thanksgiving recess. The report will outline evidence gathered by lawmakers on the panel, along with those on the House Foreign Affairs and Oversight committees.
Congressional investigators have been looking into whether Trump abused his power by pressuring Ukraine to launch investigations of former Democratic Vice President Joe Biden, who is running to unseat him in the 2020 presidential election, and a discredited conspiracy theory that Ukraine, not Russia, interfered in the 2016 US presidential election.
The president and his Republican allies in Congress say the inquiry has been unfair, because it did not allow the White House to have legal counsel present or call witnesses during weeks of closed-door testimony and open hearings before the House Intelligence Committee.
However, Republican lawmakers were able to question witnesses during the closed door hearings and called three witnesses during the public hearings that wrapped up last week.
"The president may well look at this, or his counsel may well look at this, and say: Why would we want to get in here and legitimize this process, when it was made illegitimate at the beginning by shutting us out?" said Republican Representative Tom Cole.
The House Judiciary Committee could vote on whether to recommend articles of impeachment within the next two weeks, setting the stage of a possible impeachment vote by the full House before Christmas, according to Democratic aides.
If the House impeaches Trump, the Republican-controlled Senate would hold a trial to determine whether he should be convicted and removed from office.