WASHINGTON (BLOOMBERG) - Senate Democrats are pressuring House Speaker Nancy Pelosi to end her standoff over the impeachment trial of President Donald Trump as it has become increasingly clear there is little chance of winning concessions from Senate Majority Leader Mitch McConnell.

While most House Democrats on Wednesday (Jan 8) continued to support Pelosi holding back the articles of impeachment they adopted last month until McConnell sets out his rules for the trial, several Democratic senators suggested the battle was over.

"If we're going to do it, she should send them over. I don't see what good delay does," said Democratic Senator Dianne Feinstein, Pelosi's fellow Californian.

Senator Chris Murphy of Connecticut said he hopes Pelosi will transmit the articles of impeachment soon.

"My expectation is that we'll be able to start this trial next week," Murphy said.

"The leverage over Republicans exists in the votes we take inside the trial."

In a closed-door meeting with fellow House Democrats Wednesday, Pelosi gave no hint that she was ready to set a timeline for sending the articles of impeachment to the Senate, according to lawmakers.

"We are waiting to see what the terms are," Pelosi said afterward. She said she wants McConnell to release a resolution setting out the Senate rules for the trial before she takes the next step.

"Then we'll be able to name our managers. But we can't do it until we see the arena they're going into."

There was no indication McConnell was willing to do that, and he dismissed Pelosi's attempt to negotiate the terms of trial.

"There will no haggling with the House over Senate procedure," McConnell said on the Senate floor Wednesday.

"We will not cede our authority to try this impeachment."

Representative Peter Welch of Vermont, a Democrat on the Intelligence Committee, said the Senate would be getting the impeachment articles "sooner rather then later."

Pelosi is scheduled to hold her weekly news conference on Thursday.

McConnell, who wants to engineer a quick acquittal of the president, in effect declared victory Tuesday when he announced after meeting with GOP senators that there are enough votes among Republicans to set the terms for the impeachment trial without Democratic support.

The rules, he said, would be similar to those used for then-president Bill Clinton's impeachment trial 21 years ago. That would set up about two weeks for arguments by House managers and Trump's defence, as well as senators' questions, before addressing the thorny issue of whether to end the trial without any fresh documents or witnesses. Both sides could then call for more testimony but would need 51 senators to agree.

McConnell said the Clinton precedent doesn't guarantee witnesses will testify, but it also doesn't preclude it. Still, the majority leader would be able to pressure GOP senators to stand firm against calling witnesses.

'DRAMATICALLY DIFFERENT'

Representative Dan Kildee of Michigan said Pelosi is arguing that the Clinton case is different because it grew out of the work of an independent counsel and a grand jury that got testimony from the president. The Senate did hear videotaped depositions from a few witnesses, but that was voted on after the first phase of the trial.

"All of the work that was done leading up to impeachment of Clinton was so dramatically different that there is not really an apples to apples comparison," Kildee said.

Democrats had been counting on the offer by former Trump national security adviser John Bolton to testify if subpoenaed, as well as revelations of emails and other evidence since the impeachment vote, to sway at least a few Republican senators to their side.

Rather than waiting to decide in the second half of the trial, Democrats are pressing for upfront commitments to subpoena Bolton, acting White House Chief of Staff Mick Mulvaney and others with direct knowledge of Trump's decision to withhold military aid last year while pressing Ukraine to investigate potential 2020 rival Joe Biden and his son.

Democrats also want the Senate to demand Trump cough up a trove of documents he blocked from the House.

"What's happened in the last four days, with Bolton, has made it more complicated," Representative Bill Pascrell, a New Jersey Democrat, said on Tuesday after a meeting with Pelosi.

"And we have indications there are others."

REPUBLICAN VOTES

With no expectation Trump would be convicted and removed from office - something that would require 67 votes - Democratic leader Chuck Schumer has instead looked to sway Senate Republicans who will eventually have to face the voters with their records on the impeachment question.

But even the two Republicans viewed as most likely to be open to the Democrats' arguments, Alaska's Lisa Murkowski and Maine's Susan Collins, said they backed McConnell's plan to follow the precedent of Clinton's impeachment trial. Only one Republican, Mitt Romney of Utah, said he wants to hear from Bolton, and even he declined to say whether he would vote with Democrats on issuing a subpoena.

"We are telling our Republican colleagues, you can run but you can't hide," Schumer said. "There will be votes on the four witnesses we have asked for. There will be votes on the three sets of documents that we have requested. And there may be votes on other witnesses and documents as well."

Schumer and other Pelosi allies sought to put the best face on the situation, saying the House speaker had won on key points.

"By not sending the articles immediately she's already accomplished two things," he said, referring to Pelosi. McConnell won't be able to move immediately to dismiss the articles of impeachment and in the past few weeks there has been a "cascade of evidence" that bolsters the case for witnesses and documents, he said.

"Now we have a greater feel for where we're headed," he said.

"I think she's done a very, very good job and it's helped our case."

House Intelligence chairman Adam Schiff, a California Democrat, also said the delay had an important impact by making clear that McConnell "is working in cahoots with the president as part of this cover-up."

Once Pelosi decides on sending the Senate the two articles of impeachment that the House adopted last month, she will have to schedule a floor vote on a resolution formally authorising their transmission and providing the names of House managers who will prosecute the case in the Senate, likely led by Judiciary Committee Chairman Jerrold Nadler of New York.

The key votes in the Senate will be on McConnell's partisan process resolution at the beginning of the trial, on requests for witnesses and documents in the second phase of the trial, and at the end on acquittal or conviction.