Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Democrats on Tuesday called Senate Majority Leader Mitch McConnell's initial proposal for President Donald Trump's impeachment trial "appalling," a "national disgrace," and "deliberately designed to hide the truth."

"This is just appalling," Senate Minority Leader Chuck Schumer, D-N.Y., told MSNBC's "Morning Joe," adding that McConnell, R-Ky., was seeking to turn the trial into "a farce" and that under this proposal it would be a "national disgrace."

The rules were later on Tuesday revised amid pressure from Democrats and some Republicans.

Schumer had pledged to offer amendments to change the "most egregious things" McConnell proposed, pleading for four Republicans — the number needed to form a majority — to vote with the Democrats.

"His resolution creates a trial that is rushed, with as little evidence as possible and done in the dark of night," Schumer said, adding, "If their case is so strong, why are they afraid to present it in the light of day?"

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Accusing Trump of trying "to blackmail a foreign country so they could interfere in our election," Schumer claimed McConnell was now "totally, totally, totally going along with Trump’s cover-up, hook, line and sinker."

Of McConnell's pledge to conform to the same standard the Senate used during then-President Bill Clinton's 1999 impeachment trial, Schumer said McConnell's proposal was "a far cry" from those rules.

House Speaker Nancy Pelosi, D-Calif., and the seven House impeachment managers bashed McConnell's proposal soon after Schumer's interview.

Download the NBC News app for full coverage of the Senate impeachment trial

"Leader McConnell’s process is deliberately designed to hide the truth from the Senate and from the American people, because he knows that the president’s wrongdoing is indefensible and demands removal," Pelosi said in a statement. "No jury would be asked to operate on McConnell’s absurdly compressed schedule, and it is obvious that no senator who votes for it is intending to truly weigh the damning evidence of the president’s attacks on our Constitution."

"The public now knows why Leader McConnell has been hiding his resolution: The Clinton comparison was a lie," she continued. "Clearly and sadly, Leader McConnell has misled the American people.'

The impeachment managers said McConnell's proposal "deviates sharply from the Clinton precedent — and common sense — in an effort to prevent the full truth of the president’s misconduct from coming to light."

McConnell's proposal initially allotted each side a total of 24 hours to present arguments, confined to two working days. Additionally, it suggested that none of the House evidence will be automatically admitted into the trial and that the Senate would vote later on whether to admit the documents.

But on Tuesday, McConnell appeared to walk back his initial proposal amid the backlash. The resolution read into the record allowed for each side to spread its 24 hours over three days and for evidence to be automatically admitted unless the president's legal team objects.

Arguments will begin Wednesday afternoon, according to those rules, which are expected to be adopted Tuesday.

Once both sides present their cases, 16 hours will be provided for senators to ask questions in writing. The Senate would then consider whether to subpoena witnesses and documents. If witnesses and documents are approved, McConnell's resolution makes clear that witnesses must first give their deposition, a process that typically takes place behind closed doors, before a determination over testimony is made.

In Clinton's trial, House impeachment managers had three days to deliver their arguments, using about four to six hours each day. Clinton's team also took three days to deliver its arguments, using about two to four hours each day.

On Monday, Trump's legal team argued in a brief that the president did "absolutely nothing wrong." On Tuesday, Trump said at the World Economic Forum that his impeachment was part of a long-running "hoax."

Last month, the House approved two articles of impeachment against Trump. The first article charged him with abusing his power by pushing for Ukraine to investigate former Vice President Joe Biden, his son Hunter Biden and Democrats as he withheld nearly $400 million in congressionally approved military aid to the country and an official White House visit for Ukrainian President Volodymyr Zelenskiy. The second article charged Trump with obstructing Congress' investigation into those efforts.