Video report by ITV News Washington Correspondent Robert Moore
A US House of Representatives’ panel has released a lengthy report detailing its rationale for impeachment charges, and accused President Donald Trump of betraying the nation for his own political gain.
They point to Mr Trump pressuring Ukraine to investigate 2020 political rival Joe Biden while withholding as leverage military aid the country relies to counter Russia, as well as his efforts to block the House investigation.
The US President has denied any wrongdoing and took to Twitter on Monday to brand the impeachment proceedings "the greatest con job in the history of American politics".
The House will vote on Wednesday on the impeachment articles approved last week by the House Judiciary panel.
The vote is all but certain to result in Mr Trump’s impeachment, though he is expected to be acquitted in a Senate trial.
The House Judiciary Committee detailed its case against the nation’s 45th president in a 650-page report released just after midnight.
It said Mr Trump “betrayed the nation by abusing his high office to enlist a foreign power in corrupting democratic elections”.
The judiciary panel summarised the evidence for impeachment compiled by the House intelligence committee, and said Mr Trump “has demonstrated he will remain a threat to national security and the constitution if allowed to remain in office”.
Mr Trump, by refusing to co-operate with the House impeachment inquiry, violated the constitution’s system of checks and balances, the report said.
Only the fourth US president to be charged in impeachment proceedings, Mr Trump has insisted he has done nothing wrong.
Votes are set for Wednesday in the House, but already attention is turning to the Senate trial, where the Republicans are expected to acquit Mr Trump in January.
“There ought to be a fair trial where the whole truth comes out,” Senate minority leader Chuck Schumer said on Sunday. “And I’m going to work to get that done.”
The top Senate Democrat called for new evidence and testimony from former national security adviser John Bolton, acting White House chief of staff Mick Mulvaney and two others as part of a detailed proposal outlined in a letter Sunday to majority leader Mitch McConnell to spur negotiations with the Republican Party.
“This trial must be one that is fair, that considers all of the relevant facts,” Mr Schumer wrote.
“The trial must be one that not only hears all of the evidence and adjudicates the case fairly; it must also pass the fairness test with the American people.”
Mr Trump has expressed interest in a robust trial that would not only clear him of the charges in the senate but also vindicate him, but his desire for a lengthy proceeding is something senate Republicans are hoping to avoid.
Democrats expect support for impeachment from all but a few of their members; no Republicans are expected to join them.
Mr Trump says impeachment is nothing but an effort to overturn the results of the 2016 election.
Democrats counter that, left unchecked, Mr Trump will try again to seek foreign interference in the 2020 race.