The House will take a historic vote Wednesday on sending two articles of impeachment to the Senate and approving the team of lawmakers who will prosecute President Trump for high crimes and misdemeanors, triggering only the third trial of an American president.

The roll call will come nearly four weeks after a bitterly divided House charged Trump with abuse of power and obstruction of Congress for pressuring Ukraine to launch investigations that would benefit him politically. It will end a political standoff between House Speaker Nancy Pelosi (D-Calif.) and Senate Majority Leader Mitch McConnell (R-Ky.) but set the stage for an intense partisan fight in the heat of an election year.

Pelosi informed her Democratic caucus Tuesday morning of the upcoming vote after holding the articles for weeks in hopes of extracting concessions from McConnell on calling new witnesses as part of a Senate trial. McConnell refused — but the issue is still very much front and center for moderate Senate Republicans balancing party loyalty with difficult reelection battles.

“The American people deserve the truth, and the Constitution demands a trial,” Pelosi said, announcing the vote in a statement. “. . . The president and the Senators will be held accountable.”

Hours later, the chairs of four House committees released a cache of text messages and documents provided by an associate of Rudolph W. Giuliani, Trump’s personal attorney, that revealed new details about his efforts to seek damaging information about Democrats from sources in Ukraine.

“There cannot be a full and fair trial in the Senate without the documents that President Trump is refusing to provide to Congress,” the chairs of the House Intelligence, Oversight and Reform, Judiciary, and Foreign Affairs committees said in a joint statement.

Wednesday’s vote sets in motion a ceremonial handoff between chambers, as House impeachment managers physically carry the articles across the Rotunda in a high-profile procession.

McConnell said Tuesday, however, that opening arguments are unlikely to begin for another week. He sketched out initial steps this week, with Chief Justice John G. Roberts Jr. sworn in as the presiding officer and all 100 senators, who will serve as jurors, also sworn in. Then, the Senate will break for the four-day Martin Luther King Jr. Day weekend, pushing any debate on rules governing the trial into next week.

While Pelosi didn’t announce her prosecution team Tuesday, many senior Democrats expect her to tap House Intelligence Committee Chairman Adam B. Schiff (D-Calif.), House Judiciary Committee Chairman Jerrold Nadler (D-N.Y.) and a few others close to the investigation to make the case, closing out weeks of behind-the-scenes lobbying for the starring role in the trial.

“There’s a lot of people — I mean, Adam and Jerry foremost among them — who have all of the facts at their fingertips, and they’re ready to go today,” said Rep. Peter Welch (D-Vt.). “I mean, Adam Schiff could present the case this afternoon. So could Jerry.”

The late start complicates Republicans’ plan to vote to acquit Trump before the Feb. 4 State of the Union address.

“You know, as I recall, President Clinton gave his State of the Union in the middle of that process, and I would expect — no reason to believe that same thing wouldn’t happen,” said Sen. Roy Blunt (R-Mo.).

The GOP was hoping Trump could use the annual address to pronounce himself exonerated, but now the trial could easily extend past that date, prompting some Republicans, including Rep. Jim Banks (Ind.), to float the idea of postponing the speech.

The timing also raises the prospect of impeachment spilling into the New Hampshire Democratic primary on Feb. 11. Senators running for the presidential nomination, including Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.), will soon find themselves stuck in the Senate chamber, unable to campaign — a situation already complicating any plans ahead of the Feb. 3 Iowa caucuses.

For now, how the trial will proceed depends on about half a dozen centrist Senate Republicans and whether they will buck their leadership and side with Democrats on summoning witnesses such as John Bolton. The former national security adviser likened Trump’s pressure on Ukraine to a “drug deal,” according to sworn testimony from a former deputy, Fiona Hill.

The White House stonewalled House investigators, repeatedly blocking witnesses and documents requested in the months-long impeachment probe. While Senate Republican leaders have favored a no-witness strategy, some moderates up for reelection in swing or Democratic states, including Sen. Susan Collins (R-Maine), are eager to show independence from the party in seeking a credible, robust trial.

Should four Senate Republicans agree on the need to hear more evidence, Democrats could force the issue, upending McConnell’s plans. Preemptively, Senate Republicans have warned Democrats that should they prevail on securing testimony from witnesses such as Bolton or acting White House chief of staff Mick Mulvaney, Trump’s team will be sure to call its own witnesses, possibly even Hunter Biden, the former vice president’s son who was on the board of a Ukrainian gas company.

Trump pressured Ukraine to investigate his potential 2020 rival, Joe Biden, and Hunter Biden.

On Tuesday, McConnell met with small group of Senate Republicans, including Sen. Ted Cruz (Tex.), who told the leader that as long as Democrats insisted on calling witnesses, Republicans should do the same, casting it as “witness reciprocity,” according to two Republican officials who spoke on the condition of anonymity to talk frankly. McConnell was receptive to Cruz’s argument, according to the officials. Cruz spoke about his proposal, and the possibility of seeking Hunter Biden’s testimony if Democrats push for Bolton to appear, with other Republican senators at the weekly GOP lunch.

Politico first reported on the meeting.

After the lunch, McConnell told reporters, “When you get to that issue, I can’t imagine that only the witnesses that our Democratic colleagues would want to call would be called,” McConnell said Tuesday.

Senate Republicans have been coalescing around an argument that it was the House’s duty — not the Senate’s — to question firsthand witnesses who spoke to Trump about Ukraine. The White House repeatedly rejected impeachment investigators’ summonses for members of Trump’s inner circle, but House Democrats declined to appeal to the courts to force the matter, citing the slow litigation process.

In a floor speech Tuesday, McConnell argued that congressional investigators took 14 months to look into Watergate before President Richard Nixon’s resignation and accused Pelosi of trying to short-circuit the process. “They pulled the plug early because the facts were never the point; the point was to check a political box,” McConnell said.

The push for witnesses also complicates Democrats’ internal dynamics. If impeachment managers argue during the trial that they need more evidence and additional witnesses, that could undermine their case that the facts are clear and that Trump should be removed from office.

Those “two things cannot both be true,” McConnell said. “House Democrats’ case cannot simultaneously be so robust that it was enough to impeach in the first place . . . but also so weak that the Senate needs to go fishing.”

House Majority Leader Steny H. Hoyer (D-Md.) said Tuesday that the two aren’t mutually exclusive. “We’ve made our case,” he said. “But I think the case can be amplified.”

Additionally, Sen. Richard Blumenthal (D-Conn.) argued that the House’s case was already “overwhelming” in support of Trump’s removal but that there was no harm in pushing for more.

“The case is already there — these witnesses and documents simply add to it,” he said. “They confirm it. They corroborate it.”

Not every Democrat agrees. Several warned Tuesday that it could be a mistake for the prosecutors themselves to focus on the need for additional evidence — and said they should instead rely on outside political pressure to make that case.

We don’t need witnesses to make this case. Witnesses can buttress the case, can maybe convince people with additional testimony as to the accuracy and validation of what we presented to them. But they’re not essential,” said Rep. Gerald E. Connolly (D-Va.).

Multiple Democrats, however, compared the House impeachment to a grand jury indictment — one that presents sufficient but not complete evidence for a conviction — and said it would be appropriate to push for additional witnesses.

“It’s hard to imagine how you decide this case and decide whether or not the president should be convicted of these very serious charges before us without evidence being presented by way of witnesses and documents,” said Rep. David N. Cicilline (D-R.I.). “I think obviously the impeachment managers will make that case.”

The debate over witnesses unfolds as Republicans confronted one internal dispute. Senate Republicans have rebuffed Trump’s weekend demand that their chamber move immediately to dismiss charges against him rather than hold a trial.

“Little or no sentiment in our conference for a motion to dismiss,” McConnell told reporters.

He has argued privately to the president that there would not be enough votes to dismiss the case, which could create embarrassing optics for him, according to one individual close to the senator who was not authorized to speak publicly and so spoke on the condition of anonymity.

On Tuesday, Senate Republicans emerged from the private caucus lunch largely unified on sidestepping such a vote, with Blunt arguing that “we can’t just have a one-sided process that suddenly ends.”

“This process needs to be a process where everybody is heard and . . . the person who would benefit the most from everybody being heard is the president,” Blunt said.

The move to skip a motion to dismiss is a reminder of the power held by a small band of moderates — Collins, Sen. Lisa Murkowski (R-Alaska) and Sen. Mitt Romney (R-Utah) — in determining the impeachment process. More than Trump, McConnell is listening to the demands of these senators, hoping to keep them in line with the party.

In another victory for this group, the resolution setting the scope of the trial is expected to include a provision guaranteeing a vote on whether to subpoena witnesses.

Paul Sonne, Seung Min Kim and Robert Costa contributed to this report.