US President Donald Trump is accused of abusing his power by trying to force Ukraine to investigate Joe Biden and obstructing Congress when lawmakers tried to investigate the matter.
The House Judiciary Committee on Thursday opened two-day marathon hearing to approve the Articles of impeachment against President Donald Trump.
The Committee is expected to approve two articles of impeachment later in the day, which will allow a vote by the Democratic-controlled House next week that is expected to make Trump the third president in US history to be impeached.
If the House impeaches Trump, who is charged with abuse of power and obstruction of Congress, the matter would then go to the Senate for a trial. The Republican-led chamber is unlikely to vote to remove Trump from office.
Donald Trump is accused of abusing his power by trying to force Ukraine to investigate Joe Biden, the former vice-president and leading contender for the Democratic nomination to run against Trump next year.
Trump is also accused of obstructing Congress when lawmakers tried to investigate the matter.
However, the US president denies any wrongdoing and condemned the impeachment enquiry as a hoax.
At the start of the hearing, Republicans on the Judiciary panel repeatedly complained about the procedures followed by Democrats in the impeachment inquiry.
Republicans requested another hearing and said their rights had been trampled in the inquiry but were voted down by the panel's Democratic majority.
"Rules have just been thrown out the window in this process," said Republican US Representative Debbie Lesko. "It continues to amaze me how corrupt, how unfair this process has been from the start."
Democrats noted that Republicans were not addressing the substance of the charges against Trump.
"Let us dispense with these process arguments and get to the substance of why we are here today," Democratic Representative Joe Neguse said.
Public support for impeachment has largely fallen along party lines, with the vast majority of Democrats supporting it and most Republicans opposing it. Trump's approval rating, according to opinion polls, has largely remained consistent throughout the inquiry.