Senate Minority Leader Charles SchumerCharles (Chuck) Ellis SchumerDemocrats question fairness of Senate trial after Graham, McConnell statements Turf war derails bipartisan push on surprise medical bills Senate confirms Trump's nominee to lead FDA MORE (D-N.Y.) on Tuesday dismissed out of hand a proposal from Senate Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellPoll: Support for impeaching and removing Trump dips McConnell tees up votes on 13 Trump judicial picks ahead of break Conway says White House sees 'no reason' to bow to Democratic witness demands MORE (R-Ky.) to consider the question of additional witnesses and documents later in President TrumpDonald John TrumpDemocrats secure fast-track to the floor for Canada-Mexico trade deal Mexican official says he's 'very satisfied' with USMCA after recent concern More than 700 historians sign letter calling for House to impeach Trump MORE’s impeachment trial.

Schumer said the crucial question of whether the Senate should subpoena key witnesses should be decided at the start of the trial and not be delayed while the House impeachment managers and Trump’s legal defense team spend a couple of weeks laying out their arguments on the floor.

Democrats want to call on acting White House chief of staff Mick MulvaneyJohn (Mick) Michael MulvaneyConway says White House sees 'no reason' to bow to Democratic witness demands Pro-impeachment group ramps up ads ahead of House vote, Senate trial Schumer says he tried to get McConnell to start impeachment trial talks two weeks ago MORE and former national security adviser John BoltonJohn BoltonConway says White House sees 'no reason' to bow to Democratic witness demands Pro-impeachment group ramps up ads ahead of House vote, Senate trial House Democrats want McGahn testimony even as impeachment moves to Senate MORE to testify and obtain sensitive documents the White House has withheld.

“The key issues here are witnesses and documents. We should decide those from the very beginning. In fact, many in my caucus have already voiced a fear that Mitch McConnell will ... just set up how many hours each side has to discuss things and then shut things down before we get witnesses,” Schumer said.

“We should decide witnesses and documents from the beginning and not put it off. They are the most important decisions we must make,” he added.

McConnell, however, rejected Schumer’s proposed approach earlier in the day when he noted that the resolution that launched former President Clinton's 1999 impeachment trial did not address the testimony of additional witnesses.

“What Sen. Schumer is asking for now is not the procedure that we agreed to in the Clinton impeachment,” he said, noting that the first resolution of the Clinton impeachment trial merely laid out how much time the impeachment managers and president’s defense team would have to make their arguments and how much time senators would get to ask questions.

“At that point, they dealt with the second question resolution dealing with the witness issue,” he added, noting that it takes only 51 votes to pass a motion during a Senate trial related to witnesses or additional documentation.

The GOP leader said he was optimistic about getting a deal with Schumer as long as the charged issue of witnesses is deferred.

“I’m optimistic we can agree on phase one. It’s pretty obvious we’re likely to disagree on phase two, and we’ll see at that point whether there are 51 members of the Senate who want to take one of two directions, either going in the direction of the witnesses or going in the direction of voting on the articles of impeachment,” McConnell said.

Schumer subsequently rejected that plan.

“Leader McConnell talked about a bifurcation. ‘Let’s do the early, easy stuff first.’ No,” he said.