Thousands of federal workers have begun receiving notices that they soon may face furloughs that could reduce their salaries as much as 40 percent during some pay periods because of the impasse in budget negotiations between Congress and the Bush administration.

Most of the notices warn the workers that they face the prospect of up to 22 days without pay during the coming fiscal year. Several agencies have told workers that they may face layoffs every week next year because their agencies have severe budget problems.

Under federal law, individual letters must be given to each threatened worker by Aug. 31 as a precursor to the massive budget cuts that the Bush administration has threatened to implement Oct. 15 as a result of the Gramm-Rudman-Hollings deficit-reduction law.

Although the administration is obligated to begin sending the notices, some personnel directors and union officials said the action was part of an effort to put pressure on Congress to quickly settle the budget dispute.

"A lot of this is flat-out, blatant politics," said one personnel director, who described the furlough notices as the equivalent of the government's previous, well-publicized threats to close the Washington Monument because of budget constraints.

"This time it's people," said the official, who warned that the layoffs would have devastating impact on employee morale. "How do they think the federal employees are going to keep a roof over their head and their kids in school?"

Even if the layoffs do not become reality, the country's 2.4 million federal workers -- 360,000 in the Washington area -- will have a cloud over their financial future until the issue is resolved. "The hope is that they {the layoffs} will not be necessary," said Sharon Wells, a spokeswoman for the Office of Personnel Management (OPM). "But the agencies have to be prepared."

OPM officials said that a majority of the nation's civil servants could be receiving the notices. "It's an exercise, but it's a damn serious exercise," said one OPM official.

Robert M. Tobias, president of the National Treasury Employees Union, warned that "if Congress fails to act by the first of October there are going to be furloughs, there's no doubt about that." He said the Office of Management and Budget was preparing everyone for a worst-case scenario.

John N. Sturdivant, president of the American Federation of Government Employees, which represents 700,000 federal workers, said he, too, believed there was a "real possibility" the Bush administration would go through with the furloughs.

"This is real this time," he said. "The American people are going to feel the sting of this one pretty quick and perhaps that's what the administration wants."

Sturdivant said that unlike past furlough threats when budgets were being held up in Congress because of haggling over issues such as abortion, the issues this year were much more far-reaching and harder to resolve.

Union and government personnel officials said the notices represented the first time that federal workers, not federal programs or projects, had become bargaining chips in the debate over federal spending rules.

OPM yesterday summoned personnel directors to a closed afternoon briefing at which they they outlined timetables for issuing the furlough notices.

At least two agencies have already given notices to their workers, and Labor Secretary Elizabeth Hanford Dole issued a memorandum to all Labor employees yesterday telling them they soon would be notified. "I want to emphasize that this does not mean that furloughs are a certainity, only that they may happen," she said.

Wells, the OPM spokeswoman, said the agency was not encouraging layoffs, but that it believed unpaid furloughs were "one of the least disruptive ways to the employees and to the agency's business" to make the deep cuts that the OMB has said most agencies will have to make under Gramm-Rudman-Hollings.

In a list given the personnel directors yesterday, OPM encouraged the agencies to consider hiring freezes, limit promotions and take other steps, such as delaying employee training, to keep costs down.

Under federal personnel laws, workers can be placed on unpaid leave for up to 22 days in a year. Some agencies have said their workers may have to take more than 22 days unpaid in the coming fiscal year to meet the target. OPM officials said that those layoffs will have to occur under reduction-in-force, or RIF, procedures, even though the layoffs would not be considered permanent.

An official who attended yesterday's OPM briefing said, however, that Philip Dame, a deputy associate director of OMB, "sent a strong message" to all the agencies suggesting that layoffs of more than 22 days were unlikely, but said they should be prepared to use the RIF procedures this fall.

"This is the first year we are really taking it seriously," said the personel director of an independent regulatory agency. "It's a whole new ball game."

For most small regulatory agencies, personnel costs make up about 80 percent of their budget, which means the impact of the budget cuts will be more severe on their workers.

Some may have to be furloughed as many as four days out of every two-week pay period, some directors said.

The Interstate Commerce Commission has already sent notices to its 667 eligible employees warning that they could be laid off for 108 days during fiscal 1991, a loss of about two day's pay a week.

Earlier this week, Federal Aviation Administrator James B. Busey told the 50,600 employees of his agency they could face a 25 percent pay cut under furlough plans being considered. The FAA said it would cut the work week by 2 1/2 days every two-week pay period.

Large departments, such as Health and Human Services and Veterans Affairs, also expect large-scale furloughs. At the VA, for example, officials warned that non-medical employees could face 20- to 25-day furloughs.

National cemeteries would be open only three days a week, VA officials predicted.

Presidential appointees cannot be furloughed and President Bush last week exempted uniformed military personnel from any such action.

In 1982, 42,000 federal workers, including 10,000 in the Washington area, were furloughed briefly in a budget dispute between Congress and the Reagan administration.

Staff writer Spencer Rich contributed to this report.