Updated Sunday at 11:34 a.m. ET
The White House's legal team has called the House impeachment process "highly partisan and reckless" in a forceful response to the summons issued last week by Majority Leader Mitch McConnell ahead of President Trump's Senate impeachment trial, which begins Tuesday.
"The articles of impeachment submitted by House Democrats are a dangerous attack on the right of the American people to freely choose their President," private attorney Jay Sekulow and White House counsel Pat Cipollone, who are members of Trump's legal team, wrote in a response Saturday. "This is a brazen and unlawful attempt to overturn the results of the 2016 election and interfere with the 2020 election."
Also Saturday: The seven House impeachment managers laid out the case that they will present to the Senate in the trial.
"President Trump abused the powers of his office to invite foreign interference in an election for his own personal political gain and to the detriment of American national security interests," the managers wrote in their brief. "He abandoned his oath to faithfully execute the laws and betrayed his public trust. President Trump's misconduct presents a danger to our democratic processes, our national security, and our commitment to the rule of law. He must be removed from office."
The White House response and House managers' brief are formal procedures of the impeachment trial. Sources close to the president's legal team said the White House will also file a brief on Monday.
The actions come a month after the House approved two articles of impeachment against the president, charging him with abusing the powers of his office by attempting to pressure the government of Ukraine to investigate potential political opponent Joe Biden and his son's activities there, and with obstructing Congress by refusing to cooperate in its investigation.
Last week, the House of Representatives delivered the articles of impeachment against Trump to the Senate after House Speaker Nancy Pelosi named seven Democratic members of Congress as the managers who will argue the case for impeachment. They are Reps. Adam Schiff, Jerry Nadler, Zoe Lofgren, Val Demings, Hakeem Jeffries, Sylvia Garcia and Jason Crow. Pelosi said Schiff will take the lead.
"The only remaining question is whether the members of the Senate will accept and carry out the responsibility placed on them by the Framers of our Constitution and their constitutional Oaths," the House managers wrote in the brief.
Trump denies any wrongdoing and has excoriated the process.
Robert Ray, another member of the president's defense team, told NPR's Lulu Garcia-Navarro on Sunday that the charges against Trump are not impeachable crimes.
"It's not, importantly, treason, bribery or any other high crime or misdemeanor," Ray said. "It's not bribery. It's not extortion. It's not an illegal campaign contribution. It's not any of those things. And because it is not any of those things, that is why it is not impeachable."
On Thursday, a nonpartisan federal watchdog concluded that Trump broke the law when he froze assistance funds for Ukraine. The White House has said that it believed Trump was acting within his legal authority.
The rules that will govern the Senate trial — how long it will last, how many hours a day it will go on for and other details — will be made public Tuesday when the Senate votes on a rules resolution that will formally kick off the process.
Twenty Republican senators would need to break with the president and join with all Democrats to remove Trump from office. There is little to no indication at this point that this is likely to happen — or come close.