Democrats in the House of Representatives unveiled two articles of impeachment against Donald Trump on Tuesday, accusing the US president of abusing power and obstructing Congress.
The move sets Mr Trump on course to be just the third president in US history to be impeached by the full House when the 'articles' are put to vote next week.
Speaking behind a wooden panel draped in American flags, the House Speaker Nancy Pelosi and the heads of six investigative committees said they had come to the "solemn" decision after months of investigation.
“We must be clear: no one, not even the president, is above the law,” said Jerry Nadler, the chair of the Judiciary Committee, as he announced the proposed articles of impeachment.
The first article charges Mr Trump with abusing his power by putting his political concerns over America's national interest.
To Impeach a President who has proven through results, including producing perhaps the strongest economy in our country’s history, to have one of the most successful presidencies ever, and most importantly, who has done NOTHING wrong, is sheer Political Madness! #2020Election— Donald J. Trump (@realDonaldTrump) December 10, 2019
At the centre of the case is claims Mr Trump withheld military aid to Ukraine in order to pressure the country's president to announce investigations into Joe Biden, the president's most likely opponent in the 2020 election.
The second article states Mr Trump obstructed Congress in its attempts to investigate him.
The Democrats list three examples: directing the White House to withhold documents from investigators, ordering government agencies to defy subpoenas by withholding documents, and directing officials not to co-operate with the investigative committees.
“Our president holds the ultimate public trust,” Mr Nadler said. “When he betrays that trust and puts himself before country, he endangers the Constitution, he endangers our democracy, and he endangers our national security.”
Mr Nadler stressed that the Democrats had not taken "this action lightly", but warned that Mr Trump had undermined "the integrity of our next election" and violated "his oath to the American people".
Those actions, Mr Nadler said, amounted to "committing high crimes and misdemeanours", the criteria outlined by the US Constitution outlines to trigger articles of impeachment.
Mr Trump has denied wrongdoing and called the impeachment process a "witch hunt" in a tweet, saying “Both the President & Foreign Minister of Ukraine said, many times, that there 'WAS NO PRESSURE'."
In introducing just two articles of impeachment, the Democrats hope to build their case on very specific actions, rather than including other potential allegations which could struggle to gain broad support.
In a written resolution, the first article of impeachment states that Mr Trump "abused the powers of the president" by "soliciting the interference of a foreign government" in the 2020 election through a scheme "for corrupt purposes in pursuit of personal political benefit".
The second article goes on to accuse Mr Trump of obstructing Congress by directing "the unprecedented, categorical and indiscriminate defiance of subpoenas".
The White House, which has refused to participate in the hearings in the House because it says the process is unfair, accused Democrats of engaging in a "baseless and partisan" attempt to undo the results of the 2016 election.
Adam Schiff, chairman of the House Intelligence committee, presented the Democrats' case against Mr Trump, saying the evidence of his misconduct is "overwhelming and uncontested”.
He added that the president's behaviour "goes to the heart" of whether Americans can conduct a free and fair election next November.
Nadler just said that I “pressured Ukraine to interfere in our 2020 Election.” Ridiculous, and he knows that is not true. Both the President & Foreign Minister of Ukraine said, many times, that there “WAS NO PRESSURE.” Nadler and the Dems know this, but refuse to acknowledge!— Donald J. Trump (@realDonaldTrump) December 10, 2019
“The argument, ‘why don’t you just wait?’ comes down to this: Why don’t you just let him cheat in just one more election?” Mr Schiff said.
In a statement on Tuesday, the White House press secretary Stephanie Grisham called the proposed charges a "baseless and partisan attempt to undermine a sitting president".
“They have determined that they must impeach President Trump because they cannot legitimately defeat him at the ballot box," Ms Grisham said.
She added: “The announcement of two baseless articles of impeachment does not hurt the President, it hurts the American people, who expect their elected officials to work on their behalf to strengthen our Nation."
The Judiciary Committee is expected to vote to formalise the proposed articles by Thursday and it is thought the full 435-member House will vote on the charges next week.
The chamber, where Democrats hold the majority, is almost certain to impeach Mr Trump, setting the scene for a divisive trial in the Republican-controlled Senate ahead of the 2020 election.
The White House said Mr Trump would wait to address the "false charges" in the Senate.