WASHINGTON — As House Republicans make the case for special counsel Robert Mueller to end his investigation of Russian meddling in the 2016 election, they appear ready to bring their own intelligence probe to an end.

Senior Republicans on the House Intelligence Committee tell NBC News that they hope and expect to draw their year-long investigation to an end in the coming weeks, saying they have largely completed all interviews relevant to the narrow scope of inquiry Democrats had agreed to last spring.

The committee has conducted interviews with key witnesses almost daily this month, sometimes seeing multiple witnesses on a single day, as they eyed the finish line. Though Democrats say they have requested as many as 30 additional interviews with new witnesses, none have been scheduled beyond the end of this month.

Rep. Trey Gowdy of South Carolina, one of the GOP leaders of the committee’s Russia probe, told NBC News that it is in the public’s interest to finish as quickly as possible so that they can issue a final report. He accused Democrats of wanting to prolong their work for political reasons and even downplayed the significance of the committee’s work, saying that it was the Justice Department investigation led by Mueller that would produce the most definitive final product.

“There is not a single soul with an open mind who is waiting on the House of Representatives’ Russia investigation to unlock the mysteries of the world for them,” Gowdy said. “There are people who’ve already made up their minds waiting to see whether or not their previously held conviction will be validated. But I think most people are waiting on Mueller. “

GOP Rep. Tom Rooney of Florida, who along with Gowdy and Rep. Mike Conaway, R-Texas, have overseen the panel’s work on Russia, likewise said that Democrats were seeking to needlessly extend the investigation by exploring issues beyond the agreed upon scope.

“We’re not a criminal investigation,” Rooney said in an interview. “If I honestly thought that there was fire somewhere we have an obligation constitutionally to look further into, I would have no problem doing that. But when you don’t and you’ve got to the point where you’re getting into the fifth and sixth level of people coming in here, then you’re spinning your wheels. “

Conaway, who took the lead on the Russia probe when committee chairman Devin Nunes, R-Calif., stepped aside pending an ethics investigation of his contacts with the White House on the issue, would not go as far in signaling an end point to the committee probe.

“We’re working hard to finish it. But I’ve got no timeline in mind,” he said. Among the witnesses to appear this week, CNN reports, are former DNC Chair Debbie Wasserman Schultz as well as music publicist Rob Goldstone, who helped arrange a meeting between officials from the Trump campaign and a Russian lawyer who was offering information on Hillary Clinton's campaign.

But Democrats point out that Republicans are rebuffing their requests to bring in additional witnesses or obtain relevant documents while rushing to avoid extending the probe into an election year.

“I’m increasingly concerned that pressure from outside the building from the president, from Steve Bannon and their allies to shut us down is having its effect,” said Rep. Adam Schiff of California, the ranking Democrat on the Intelligence Committee. “We have a lot of investigative work to do. If they do shut the [investigation] down it will represent a breach of the promise that the Republicans made to follow the facts wherever they lead.”

Schiff noted that while lawmakers will be consumed with tax reform legislation and a spending bill next week, committee staff will travel to New York to interview a witness Democrats have sought to question for months.

“All too often when we interview witnesses and they provide leads that we need to corroborate or that we need to investigate further, my colleagues won’t allow those,” Schiff told NBC News. “That’s not a serious investigation. That’s going through the motions.”

Gowdy, who also chairs the House Oversight Committee and presided over a select committee investigating the 2012 Benghazi attack, said congressional probes are inevitably colored by politics.

“There are Democrats on [the committee] that earlier this year were talking about collusion. When you reach the conclusion and then go looking for the facts to support it, it is a very different journey than if you do not,” he said. “And I am sure that there are Republicans who would say nothing wrong was done no matter what facts come out."

Both the House and Senate Intelligence Committees are conducting inquiries into the Russian efforts to influence the presidential election and whether Trump campaign officials may have actively colluded with them.

The House committee agreed in March to focus its investigation on four key questions: What active measures Russia took against the United States and its allies; did any active measures include links between Russians and Americans involved with the campaign; how did the U.S. Government respond, and what needs to done to prevent similar efforts in the future; and whether there were leaks of classified information from the Intelligence Community’s assessment of Russian interference.

The Senate’s probe has largely been driven by its professional staff, who have conducted most of the witness interviews. In the House, though, it is most often the members themselves acting as interrogators.

That dynamic has made it more likely that some witness testimony has leaked to reporters and given both parties ammunition to criticize one another for politicizing its work.

The panel’s Dec. 6 interview with Donald Trump Jr. seemed to magnify the divisions on the panel. Democrats said Republicans went out of their way to support the president’s son in efforts to avoid answering serious questions. The GOP members say the Democrats needlessly extended the session by asking the same questions repeatedly even if they had exhausted particular lines of inquiry.

“Some of the questions were spot on. They were exactly what you would want to have asked. And then there was the other five hours,” Gowdy said.

One Democratic lawmaker said Republicans’ treatment of key Trump officials has been so tame that at times the interviews have seemed more like auditions for roles in the Trump administration. Gowdy, for instance, stepped in to instruct Trump not to give in to Democrats’ repeated efforts to pin him down on issues related to a 2016 Trump Tower meeting with a Kremlin-connected lawyer or his father’s past real estate dealings with Russians.

It recalled a scene months earlier when Jared Kushner appeared before the committee. The president’s son-in-law had initially agreed to stay only for two hours, but several times agreed to extend the session as Democrats had more questions. When he at one point offered to stay another 15 minutes, Gowdy interjected to advise him not to.

“You can stay all day. They’re never going to run out of questions,” Gowdy told Kushner. “If that’s your intent, to just stay 15 more minutes so they’ll walk out and say you answered all their questions, that’s never going to happen.”

Gowdy confirmed both instances happened as described.

“I’m quite certain they didn’t like it when I said that. I’m also quite certain that it was closer to supper time than it was to breakfast time when I said it,” he said in the case of the Trump interview.

Only two interview transcripts have been released publicly. Rooney and Gowdy both said they expect a final report from the committee would include transcripts of most if not all interviews, with redactions made as necessary to protect classified information.

“We’ve all heard the same thing in that room. We’ve all heard the same exact testimony. I hope that this report can include a lot of [it],” Rooney said.

Rooney said he hoped that the final report would be signed by members of both parties, in keeping with the committee’s history of acting in a bipartisan, even nonpartisan way. But he conceded Democrats may not do so, and issue their own separate report.

“If that’s the case, people are going to look at it as a political document on both sides. And that would be unfortunate,” he said.

Schiff said his and Conaway’s goal has always been to issue a joint report, but that a move by Republicans to prematurely end the investigation “would make that impossible.”

“Democrats are not going to sign off on an incomplete investigation,” he said. “Democrats will do our best to continue the investigation, and Bob Mueller will continue to do his. And as new facts come to the surface, they’ll have to justify that.”

Former Kansas Rep. Dan Glickman, who served on the Intelligence Committee for eight years including two years as chairman, said in an interview that the panel has, with few exceptions, been one of the least partisan in Congress. He recalled the seriousness with which members of both parties handled an investigation into the circumstances surrounding Aldrich Ames, a CIA operative who was caught selling national security secrets to the Soviet Union.

"What you're seeing on the Intelligence Committee is just a symptom of the underlying problems in the House of Representatives,” he said. "The intelligence committees' processes are part of our institutions of government that we have to preserve. The leadership of Congress should have as one of its basic responsibilities to get these folks to work together in a bipartisan way.”