'No one is above the law': Nancy Pelosi announces formal impeachment inquiry of US President Donald Trump
Video report by ITV News Washington Correspondent Robert Moore
US House Speaker Nancy Pelosi has announced a formal impeachment inquiry into Donald Trump over allegations that he pressured Ukraine's leader to investigate Joe Biden’s family.
Announcing the move, the Speaker of the United States House of Representatives said: "The President must be held accountable, no one is above the law."
Ms Pelosi had for months resisted calls to start the impeachment process but on Tuesday said: "The actions taken to date by the president has seriously violated the constitution, especially when the president says Article 2 says 'I can do whatever I want'."
However Trump has since responded to the announcement on Twitter, branding the formal inquiry as "presidential harassment" and a "total Witch Hunt!"
Earlier he said that the US is "doing the best it's ever done" and that Democrats are going to lose next year's elections.
Ms Pelosi said: "The actions of the Trump Presidency revealed a dishonourable fact of the President's betrayal of his oath of office, betray of national security and betrayal of the integrity of our elections."
She added: "Therefore today I am announcing the House of Representatives moving forward with an official impeachment enquiry."
Nancy Pelosi announces the house is pushing forward with the formal impeachment inquiry of US President Donald Trump
Joe Biden, who is running for presidency in the upcoming US election, spoke earlier from his hometown of Wilmington, Delaware.
He said: "We have a president who believes he can do anything and get away with it."
"We have a president who believes he is above the law," the former vice president added.
His comments came as more than 100 Democrats announced they are backing impeachment proceedings against the US president.
So why are they calling for Trump to be impeached?
The calls have been prompted by Democrats who are questioning whether Trump improperly used his office in a phone call with Ukraine's new leader Volodymyr Zelensky.
But the US President earlier tweeted that he would disclose the full transcript of the phone call.
The US president is reported to have spoken about corruption, frozen U.S. millions and Democratic rival Joe Biden.
The administration is withholding a whistleblower complaint at least partly related to that matter from Congress.
"Now is the time to act," said Rep. John Lewis of Georgia, the civil rights icon, in an emotional address to the House by the 70-year-old lawmaker who is often viewed as the conscience of the chamber's Democrats.
"The time to begin impeachment proceedings against this president has come," Lewis said.
He said he has been patient but now, "To delay or to do otherwise would betray the foundation of our democracy."