Correction: An earlier version of this article incorrectly stated that escalator maintenance would be reduced at the D.C. Superior Courthouse as a result of the sequester. Some building maintenance, but not escalator work, has been reduced. The article also incorrectly stated that Superior Court spokeswoman Anita Jarman confirmed that, as a result of the sequester, a judicial training event was moved from a resort in Pennsylvania to a local venue. The training’s move was confirmed by multiple sources, but Jarman was not one of them. This version has been corrected.

Federal courthouses in the Washington region will keep their doors open in the face of mandatory spending cuts, but some key players in the courtrooms are likely to be missing.

Federal prosecutors, public defenders and U.S. marshals, all critical to the daily work at U.S. district courts in Maryland, Virginia and the District, have been told to plan on the possibility of taking more than a dozen furlough days beginning as soon as this month.

To accommodate absences, U.S. District Judge Royce C. Lamberth, chief of the federal court in the District, is preparing to call off criminal proceedings every other Friday beginning April 26.

Lamberth said that he hopes the scaled-back schedule is temporary but that “the real question is, what happens next year? We just don’t know.”

Judicial leaders are warning Congress that the federal spending cuts known as sequestration could jeopardize the court system’s ability to carry out its constitutional mission. The automatic cuts, they said, will result in delays in trials; fewer probation officers to supervise felons released into the community; and less money for court-ordered drug testing and courthouse security.

At the District’s two local courts, which rely heavily on federal funding, the effects will be more physical. Hallways, restrooms and courtrooms will not be cleaned as often. There will be less money to control the well-known rodent problem at D.C. Superior Court.

“Clearly, this is not ideal,” said Anita Jarman, a Superior Court spokeswoman. Also, a training conference for judges that was to be held at a golf and spa resort in Pennsylvania has been moved to a local venue to save money, according to several courthouse sources who spoke on condition of anonymity.

Hardest hit by the judicial cuts are public defenders. Starting this month, the lawyers appointed to represent the region’s poor in federal cases in District Court will be forced to take as many as 27 days of unpaid leave by the end of September.

For public defenders in Northern Virginia, the cuts add up to about three weeks of furloughs.

“It’s tremendously demoralizing, even for people who are used to fighting against extraordinary odds,” said Michael S. Nachmanoff, the federal public defender for the Eastern District of Virginia, which includes Alexandria and Richmond. “These cuts are devastating. At some point, the program can’t survive.”

Nachmanoff, whose budget is controlled by the Judicial Conference of the United States, worries that his staff attorneys might leave and that the office eventually might not be able to handle as many cases.

The federal public defender’s office in Maryland has passed on some cases involving costly travel for investigations or expert witnesses. Those cases are instead sent to court-appointed private lawyers.

“We hate doing it, because we’re supposed to take those cases,” said Maryland’s federal public defender, James Wyda, whose lawyers have begun taking the first of up to 20 furlough days. “It’s a very difficult time for our lawyers and our program, and I think it’s a sad day for our justice system.”

Judicial leaders recently urged congressional budget writers to recognize the “uncontrollable nature” of the judiciary’s workload, determined by the volume of cases filed with the courts and its constitutional mandates. Overall, sequestration has trimmed federal judiciary funding by nearly $350 million, or 5 percent.

“The federal court system cannot continue to operate at this level,” Judge Julia S. Gibbons, who heads the Judicial Conference’s budget committee, told a House appropriations subcommittee. Gibbons, who sits on the U.S. Court of Appeals for the 6th Circuit, called the cuts “unsustainable, difficult and painful to implement.”

“We don’t choose our work. Other people choose what comes to us, and we have to meet those demands,” she testified.

Because of sequestration, the Justice Department has estimated that prosecutors throughout the country will handle 1,600 fewer civil cases and 1,000 fewer criminal cases.

“Fewer affirmative civil and criminal cases will affect our ability to ensure that justice is served and impact funds owed to the government,” according to a statement from the department.

Federal prosecutors in local U.S. attorney’s offices have been told to prepare for no more than 14 furlough days starting April 21, but it is uncertain whether any unpaid days will be necessary. In a March 28 memo to Justice Department employees, Attorney General Eric H. Holder Jr. said that the department “needs more time to determine if we can avoid furloughs” and that he would make that decision in mid-April.

On furlough days, employees may not “serve as an unpaid volunteer and must remain away” from their workplaces, according to a February letter describing possible furloughs.

Although the District’s federal court plans to cancel criminal proceedings on alternate Fridays, Lamberth said a magistrate judge will be on call to handle initial appearances for people arrested Thursday evenings.

In Northern Virginia and Maryland, there are no formal plans to postpone criminal cases. U.S. District Judge Deborah K. Chasanow, chief of the Maryland federal court, said she has encouraged judges to delay hearings, when possible, to accommodate furloughs.

“We can limp along for the rest of this year. But if this continues, if we don’t get some relief,” she said, “it gets very, very bad.”