House Speaker Nancy Pelosi said the House will prepare to send articles of impeachment against President Donald Trump to the Senate next week after failing to secure any concessions on the Senate trial from Republicans.

“I have asked Judiciary Committee Chairman Jerry Nadler to be prepared to bring to the floor next week a resolution to appoint managers and transmit articles of impeachment to the Senate,” Pelosi wrote in a letter to House Democrats on Friday. “I will be consulting with you at our Tuesday House Democratic Caucus meeting on how we proceed further.”

With the letter, Pelosi ends a three-week standoff with Senate Majority Leader Mitch McConnell over rules for what would be only the third impeachment trial of a U.S. president in the country’s history.

Naming the House impeachment managers, who will serve as the prosecutors in the Senate proceedings, and transmitting the two articles will trigger the start of a trial that may take several weeks.

Senate Democratic leader Chuck Schumer has been pressing for a guarantee of additional witnesses and evidence at the trial. McConnell, however, has made clear he has no interest in or need to compromise and has insisted that the Senate would follow the template for President Bill Clinton’s impeachment trial in 1999.

That would defer any vote on hearing witnesses or reviewing new evidence until after the House managers and Trump’s lawyers make their cases. Four Republicans could join with all Democrats to provide a majority in favor of hearing witnesses. Or, 51 of 53 Republicans in the Senate could vote to dismiss the case without additional evidence.

Pelosi hasn’t made a specific demand -- saying only that she wants to see the rules for how the impeachment trial will be conducted.

Pelosi argued on Thursday that during the weeks since the House adopted the impeachment articles on Dec. 18, new documents that Democrats see as pivotal emerged, and a key witness, former Trump National Security Adviser John Bolton, has said he’s willing to testify to the Senate under subpoena.

“Every senator now faces a choice: to be loyal to the president or the Constitution,” she wrote in her letter.