On the eve of his expected impeachment, US President Donald Trump on Tuesday told the opposition Democrats' leader in Congress that the move to oust him from office is an attempted "coup" that is "subverting America's democracy."
In an extraordinarily angry letter of more than five pages, Mr Trump told Nancy Pelosi, Speaker of the House of Representatives, that "history will judge you harshly."
He maintained that he did nothing wrong in seeking a foreign investigation of political rivals, and attacked Democrats for focusing on impeachment rather than other issues.
Mr Trump said he did not believe the letter would change anything, but he was writing it to register his objections “for the purpose of history".
He said he had been given less rights than "those accused in the Salem witch trials" in the US during the 17th century
The Democratic-led House is expected to impeach the president for abuse of office in a vote on Wednesday.
Mr Trump is accused of dealing with Ukraine to help himself politically and then obstructing Congress by blocking the investigation.
It will make him the third president to be impeached in American history.
Meanwhile on Capitol Hill, House Democrats and Republicans sparred over the rules of debate for Wednesday’s historic votes on impeaching Mr Trump.
Senate Majority Leader Mitch McConnell on Tuesday made it clear that he was not interested in giving in to any demands from the Democrats.
Mr McConnell said that the partisan House impeachment would result in “an almost entirely partisan outcome in the Senate as well.”
“This is a political process,” he said. “I’m not impartial about this at all.”
No Republicans are expected to vote to impeach Mr Trump.
But one by one, Democrats are building a majority from their ranks as politicians, including many new legislators who could risk re-election in autumn from districts where Mr Trump is popular, announced they would vote for the two articles of impeachment.
“We must impeach this president,” said House Democrat Chrissy Houlahan of Pennsylvania, an Air Force veteran who is among a group of newly elected former national security officials calling for impeachment.
“I grieve for our nation. But I cannot let history mark the behaviour of our president as anything other than an unacceptable violation of his oath of office.”
Ms Pelosi, who warned against pursuing a strictly partisan impeachment, is now all but certain to have the numbers.
Attention is now shifting to the Senate which, under the constitution, is required to hold a trial on the charges. It is expected to begin in January.
Mr McConnell’s remarks effectively closed the door on talks for a deal proposed by the Democratic leader, Senator Chuck Schumer, who wants to call top White House officials for the Senate trial.
“If House Democrats’ case is this deficient, this thin, the answer is not for the judge and jury to cure it here in the Senate,” he said.
“The answer is that the House should not impeach on this basis in the first place.”
Mr McConnell is facing criticism for saying he was taking his “cues” from the White House for the expected trial.
Republicans say Mr Schumer acted similarly two decades ago when the Senate prepared to vote on president Bill Clinton.
