WASHINGTON — House Democrats are escalating their showdown with the Trump administration with open threats to fine — or even jail — officials found in contempt of Congress.

The growing frustration among Democrats seeking to press forward with a variety of committee investigations in the wake of special counsel Robert Mueller's report comes as the White House has sought to stonewall them over requests for documents and testimony from administration officials. And with some in their ranks continuing to push for impeachment hearings, Democratic leaders have vowed to be more aggressive with the administration.

Rep. Elijah Cummings, D-Md., chairman of the House Committee on Oversight and Reform, acknowledged Tuesday that jail is an option for administration officials who don’t comply.

“I said there is no tool in our toolbox that we should not explore. We will look at all those tools from a very practical standpoint,” Cummings told reporters. “It may be that we just want to deal with fines, I don’t know, but it’s either fines and/or prison.”

A number of committees are in a standoff with the president and the administration over a variety of issues ranging from his finances to the census to Mueller's report.

The president said last week that his administration is "fighting all the subpoenas" that Congress has issued or might issue for individuals or documents. "The subpoenas are ridiculous," Trump said, "I have been the most transparent president and administration in the history of our country by far."

Cummings' acknowledgement has elevated the discussions that have been taking place among rank-and-file members in recent days as the administration continues to block House Democrats from access to documents and testimony.

“I don’t think it’s anyone’s first choice” to seek jail time for officials, Rep. David Cicilline, D-R.I., told NBC News. “We recognize that it is an extraordinary remedy but we also recognize that if the president is successful in stonewalling and engaging in protracted litigation to run the clock out, he’ll be denying the American people access to the truth.”

Frustrated lawmakers are aware that executive branch noncompliance takes months or even years to resolve in the court system. And a third way to compel a witness to testify is unlikely to see any results. A U.S. attorney can file criminal charges, but it’s unlikely that Attorney General William Barr would direct a U.S. attorney to act.

The House Judiciary Committee is currently in a back-and-forth with Barr over his testimony scheduled for Thursday. He testified Wednesday before the Senate Judiciary Committee.

After the administration initially refused to make former White House security director Carl Kline available and told him to ignore a subpoena, Kline will sit for an interview Wednesday with the House Oversight Committee over his role in issuing security clearances for White House officials, including presidential adviser Jared Kushner. But Cummings said he remains skeptical about Kline's level of cooperation and will “determine whether we then have to go to the next stop” immediately after his appearance.

And the Department of Justice has said that it would not allow John Gore, a deputy assistant attorney general, to appear for a deposition before the House Committee on Oversight and Reform over a disagreement about the counsel he’s allowed to have in the room. The IRS, under the directive of Treasury Secretary Steven Mnuchin, has missed two deadlines imposed by the House Ways and Means Committee to hand over the president’s tax returns.

Rep. Gerry Connolly, D-Va., and a member of the House oversight committee, said that Congress has the ability to investigate and those who don’t comply “do so at your peril.”

“We will use every and any power in our command to compel you,” Connolly said. “You had better lawyer up. You had better be ready for serious fines. Better be ready for possible jail time.”

“We will use every available legal means to make sure that the administration complies with our constitutional responsibility to conduct oversight on behalf of the American people,” Rep. Hakeem Jeffries of New York, chairman of the House Democratic Caucus, said.

Jailing a witness held in contempt of Congress would be a drastic step that hasn’t been used in more than 80 years. While a constitutional showdown between Congress and the administration is not new, it has evolved over the centuries.

The Supreme Court now sits where Congress’ jail used to be. While members talk about fines, there is no record of a Congress actually fining those in contempt, moving it into uncharted territory.

Connolly said that a lack of congressional jail space doesn’t impede their ability to imprison.

“As you know, we have jurisdiction over the District of Columbia, and they have a beautiful jail with plenty of room that I think that would be just perfect for these people to contemplate their actions and judgment,” Connolly said.

The administration’s stonewalling is also fueling discussion of impeachment. “The combination of the Mueller report and the act of reckless defiance of the will of Congress to do its job is pushing a lot of Democrats like me to do more,” Connolly said.