Nancy Pelosi signs the articles of impeachmeny during an engrossment ceremony prior to them being walked across the Capitol to the Senate. Photograph: Shawn Thew/EPA
The House of Representatives transmitted articles of impeachment against Donald Trump to the Senate on Wednesday, setting in motion a trial that could unearth damaging new evidence of misconduct by Trump as the 2020 presidential contest heats up.
The House approved a resolution to transmit two articles of impeachment on a mostly party-line vote of 228-193, hewing closely to the tally by which the articles were approved last month.
Addressing her colleagues on the House floor, the speaker, Nancy Pelosi, sharply rejected criticism by Republicans that she had delayed transmission of the articles.
“Don’t talk to me about my timing,” she said. After months of resisting calls “from across the country” for Trump’s impeachment, she said, Trump ultimately “gave us no choice. He gave us no choice.”
Trump was impeached in December for abuse of power and for obstruction of Congress relating to a scheme in which he pressured Ukraine to announce false investigations of the former vice-president Joe Biden and then fought an inquiry into the scheme.
The Republican Senate majority leader, Mitch McConnell, said the chamber would take up “housekeeping” items relating to impeachment this week and hold opening arguments next Tuesday.
“We’ll pledge to rise above the petty factionalism and do justice for our institutions, for our states and for the nation,” McConnell said in a speech on the Senate floor.
Following the vote on Wednesday, Pelosi signed the articles of impeachment, which were placed in folders and moved in a procession at sunset from the House to the Senate. The Senate invited House members to return to formally “exhibit” the articles on Thursday.
At about 2pm on Thursday, John Roberts, the chief justice of the US supreme court, who will preside at the trial, will be sworn in by the president pro tempore of the Senate, Iowa’s Chuck Grassley, McConnell said. Roberts will then swear in the senators, and the chamber will issue a writ of summons inviting Trump to the trial.
The proceedings will then adjourn until early next week.
Earlier on Wednesday, Pelosi revealed the seven-member team, known as impeachment managers, who will prosecute the case against Trump at the Senate trial. The team includes six lawyers and will be led by Adam Schiff, the intelligence committee chair, and Jerry Nadler, chair of the judiciary committee.
The group includes women, two African Americans and one Latina – a stark contrast with the all-white and -male teams of prosecutors in the Senate impeachment trials of Andrew Johnson in 1868 and Bill Clinton in 1999, both of which ended in acquittal.
Trump is the third president in US history to face an impeachment trial in the Senate – and possible removal from office, although that is a distant likelihood, with Republican loyalists vowing to protect him.
The White House released a statement saying “President Trump has done nothing wrong” and “expects to be fully exonerated”.
No US president has ever been removed through impeachment, though Richard Nixon resigned in the face of the prospect. A two-thirds majority of senators present would be required to remove Trump.
“What is at stake here is the constitution of the United States,” Pelosi said. “This is what an impeachment is about. The president violated his oath of office, undermined our national security, jeopardized the integrity of our elections.”
While Trump’s removal is unlikely, the trial holds political hazards for him. He succeeded in enforcing message discipline among Republicans as impeachment moved through the House last fall, but there were indicators that the conduct of some Republicans in the Senate would be more difficult to manage.
A group of moderate Republicans has expressed openness in recent weeks to hearing from witnesses and a desire to weigh the charges against Trump on the merits. Those positions could quickly wither under personal pressure from Trump, who has directed rage at any suggestion that his conduct was less than perfect.
House Republicans responded vigorously to Trump’s demands that they defend him, offering worshipful assessments of Trump’s conduct, which they said was motivated by Trump’s desire to fight corruption in Ukraine.
But that posture may become more difficult as new evidence continues to emerge of Trump’s alleged wrongdoing. On Tuesday night, House Democrats released newly gathered evidence including a handwritten note by a Trump associate describing a plot involving the Ukrainian president, Volodymyr Zelenskiy, and Biden.
“Time has been our friend in all of this because it has yielded incriminating evidence, more truth, into the public domain,” Pelosi said.
In preparation to receive the articles of impeachment, the Senate leadership on Wednesday circulated rules of decorum for the trial. The rules require senators to be in attendance “at all times”, to stand at their desks when the chief justice enters the chamber, to maintain silence during the proceedings and not to bring along phones or other electronic devices.
The trial was expected to last at least two weeks, but it could go on for much longer if the sides begin calling witnesses. Certain potential witnesses, such as the acting chief of staff, Mick Mulvaney, and former national security adviser John Bolton, might be able to fill in details of an alleged scheme in which Trump withheld almost $400m in military aid appropriated by Congress to achieve his personal political ends.
The White House declined to rule out going to court in an attempt to block Bolton and other witnesses testifying.