PROVIDENCE, R.I. (AP) — The lawyers who defend the nation's poor in federal courts across the country are grappling with budget cuts they say will decimate their offices, delay criminal cases and jeopardize the fairness of the criminal justice system.

The cuts have already forced some offices of federal defenders to lay people off, and many are planning to force staffers to take off six weeks or more without pay over the next six months. Even a Supreme Court justice has expressed concern that cuts could pressure the system and result in criminals running free.

The cuts, amounting to roughly 10 percent of this year's budget, come in a program seen as the flagship for public defenders and as the nation marks this month's 50th anniversary of the landmark Supreme Court decision Gideon v. Wainwright, which guaranteed that criminal defendants will be provided with a lawyer if they can't afford one.

While federal prosecutors have been notified by the U.S. Department of Justice that they may be furloughed for up to 14 days, those cuts are not yet final. Federal public defenders, though, say cuts to their offices are virtually certain.

"It's important that people who don't have any power and any voice have people to speak for them," said U.S. District Judge Catherine Blake of Maryland, who helps oversee the federal defenders program for the judiciary. "You never know when you might need the 6th Amendment."

Defenders and court officials alike said some people will be held in prison longer while they await trial, costing taxpayers money. Justice Stephen Breyer testified this month before a House appropriations subcommittee that some people could be wrongly convicted while the real culprits remain free. Those who do not receive adequate representation could then appeal their convictions, costing the courts time and money.

Public defenders in eastern Virginia will be furloughed for six weeks without pay between April 1 and Sept. 30. In Connecticut, it will be nearly that long — 28 days. In Arizona, 10 people have been laid off and the remaining staff will be furloughed for nine days. In Massachusetts, Rhode Island and New Hampshire, it will be more than three weeks.

In many districts, defenders said, staff members who sometimes work six or seven days a week are demoralized and worried about paying their mortgages, college tuition for their children and staggering student loans. Miriam Conrad, federal defender for Massachusetts, New Hampshire and Rhode Island, said some staff members have asked if they can take second jobs to pay the bills, something she has never seen in 21 years working in the office.

Several defenders warned of a slow-moving disaster that will get worse as the months wear on and delays pile up. They also worried that this year's furloughs are not the end, and that even as the government brings more complex and time-consuming prosecutions such as mortgage fraud, they will be forced to lay more people off because of an appetite for cost-cutting in Washington.

Some federal courts have said they will not hear criminal cases on one day per week, or are considering such a plan, because of the planned furloughs of defenders and potential furloughs of U.S. marshals and prosecutors. The U.S. District Court in Delaware, for example, would not hear criminal cases on Fridays, except emergencies, said Clerk of the Court John Cerino.

Ron Sullivan, a professor at Harvard Law School and director of its criminal justice program, said the cuts raise constitutional concerns.

"Average, everyday citizens should care because the quality of justice experienced in America could potentially diminish with these cuts," he said. "Most Americans, in my view, believe that everyone has a right to a fair trial. When people have lawyers that are either under-resourced or ill trained, they do not get a fair trial."

Michael Nachmanoff, federal defender for eastern Virginia, said his office was notified just a few weeks ago of the magnitude of the cut, which must be made up before Sept. 30. A little more than half is due to the automatic budget cuts known as the sequester. The rest is a cut for the fiscal year of the budget for the federal judiciary, which funds the federal public defender system.

Nachmanoff's office has represented high-profile and time-and-money-intensive cases, such as Sept. 11 conspirator Zacarias Moussaoui and Somali pirates.

"If a new case came in that required an enormous amount of resources, death penalty, international terrorism, we would have to decline that case," he said. "That is a terrible position to be in. We are the lawyers best able to represent people in complex cases. We get the best outcomes most cost effectively."

In some cases, the people he represents provide valuable information to help the government, Nachmanoff said. But when the wheels of justice are turning slower, that could hurt such investigations.

If public defenders can't take a case because they don't have the staff, the person will instead be assigned a private lawyer, who charges the government $125 per hour, far more expensive than what it costs a public defender.

"You pay them $125 per hour every hour that they work on the case. If they have to drive three hours because (their client is) in remote detention, the taxpayer's paying for that. It's crazy," said Jon Sands, defender in Arizona and chair of the Defender Services Advisory Group, which advises the federal judiciary.

Sands said a handful of the nation's 94 federal defenders' offices are facing more than eight weeks of furloughs. More than nine plan 30 days or more, and the majority will have to furlough staff for between 15 and 25 work days.

Nearly all the defenders' budgets are spent on salaries, but they also pay for expenses such as investigators, interpreters and experts in areas such as fingerprinting or forensic accounting. Conrad, who is based in Boston, said many of those expenses can't be eliminated without compromising the quality of their defense.

Breyer told congressional members this month that he believed funding to defenders is "below the level that would be minimal." Justice Anthony Kennedy said during the same hearing that 0.2 percent of the federal budget goes to the court system, and of that, just one-seventh goes to federal defenders. That amounts to an annual budget of around $1 billion.

Sands called that "infinitesimally small."

"One of the reasons this country is great and that we have by far the best legal system is that we protect rights. We protect rights of everyone, the rich and the poor. We protect rights because it is important," Sands said. "A small amount of money could make a huge difference."