Federal corrections officials will begin transferring 125 nonviolent offenders from halfway houses to regular prisons this month as part of a Justice Department crackdown on white-collar criminals, who will no longer be able to evade prison by serving time in low-security community facilities.

The new policy means that hundreds of other white-collar defendants, including some of those caught up in the financial scandals at Enron, WorldCom and other corporations, also have lost a detention option used by the U.S. Bureau of Prisons (BOP) for nearly two decades.

Under the old policy, federal prisons officials allowed many first-time nonviolent offenders to serve their sentences in community corrections centers -- halfway houses -- rather than prison.

Defense attorneys, and many federal prisons officials, supported the approach as a way to ease prison crowding and encourage rehabilitation of low-risk criminals. But many federal prosecutors have long complained that the policy allowed wealthy criminals to circumvent federal sentencing guidelines.

"These white-collar defendants were getting a benefit that was not available to non-white-collar defendants," one longtime former federal prosecutor said. "It tended to be the situation where, if you were richer and whiter than your typical defendant, you could find all these ways to get to a halfway house."

After a legal review by Justice Department lawyers, Deputy Attorney General Larry Thompson issued an unusual rebuke last month to the head of the prisons bureau, Kathleen Hawk Sawyer, arguing that corrections officials had overstepped their authority in allowing prison sentences to be served in halfway houses and had undermined the deterrence value of real prison time.

Officials said the Justice Department review was prompted by a federal judge's complaint in a West Virginia tax-fraud case. They acknowledged that the policy change also could have a big impact on financial executives convicted of federal crimes because they will have less hope of evading prison time.

"The message is that we are not going to be treating white-collar criminals any differently than the law mandates," Justice spokesman Mark Corallo said. The new policy, first reported by Newsweek magazine, is also likely to affect hundreds of cases working their way through the judicial system.

The new approach has come under fire from the defense bar and prisoner advocates, who say it will increase crowding and decrease the chances for prosecutors to strike deals with low-risk offenders.

"It's a cheap political trick on the part of the people who have done this," said Elizabeth Alexander, director of the National Prison Project of the American Civil Liberties Union. "It raises very serious questions given that this is what BOP has traditionally done, and it is viewed as a reasonable option by federal judges."

Raag Singhal, co-chairman of the corrections committee at the National Association of Criminal Defense Lawyers, said removing halfway houses as a sentencing option runs counter to recent trends in state judicial systems, which are increasingly turning to community corrections as a way to save money and ease prison crowding.

"I don't think it's going to do anything to increase the public's confidence in the treatment of white-collar criminals," said Singhal, an attorney in Fort Lauderdale, Fla., who represents several clients affected by the new policy. "They can do much more good at a halfway house than any prison."

Linda Smith, a BOP spokeswoman, said about 600 federal prisoners are in halfway houses as part of "direct court commitments," in which a federal judge recommended a detention more lenient than prison. About 125 of those prisoners -- all of whom had more than 150 days remaining on their sentences as of Dec. 20 -- will be transferred to prisons beginning later this month, Smith said.

The new policy will not affect the use of halfway houses as a transitional point for prisoners nearing the end of their sentences, officials said. About 8,600 of the federal government's 164,000 prisoners are now in halfway houses.

The original policy allowing the use of halfway houses for imprisonment was rooted in a 1985 legal opinion by the BOP's general counsel, Smith said. But in a review of the issue, the Justice Department's Office of Legal Counsel found that the prisons bureau had overstepped its legal authority in adopting halfway houses as a detention option.

"Community confinement does not constitute imprisonment for purposes of a sentencing order, and BOP lacks clear general statutory authority to place in community confinement an offender who has been sentenced to a term of imprisonment," M. Edward Whelan III, principal deputy assistant attorney general, wrote in a Dec. 13 legal opinion. "BOP's practice is therefore unlawful."

Sawyer, the head of the prisons bureau, notified federal judges and other court officials of the legal opinion and policy change Dec. 20. Halfway house inmates began receiving letters Dec. 23 notifying them that they would be transferred to regular prisons in late January or early February.

One defendant in the Midwest, who asked that her name not be used, has been notified that she will go to a prison more than 1,000 miles from her home rather than live in a halfway house nearby. "They're saying I can't work, I can't see my family and the sentence the judge imposed doesn't matter," said the woman, who pleaded guilty to a fraud charge as part of an agreement with prosecutors. "I would never have agreed to this if I had known it would turn out like this."