If Democrat Sharon Pratt Dixon is elected mayor and tries to implement a key campaign pledge to fire 2,000 middle- and upper-level employees to reduce the deficit, she may be in for a rude awakening, according to experts on the D.C. personnel system.

Under D.C. personnel rules, if a manager's job is eliminated, he has the right to "bump" a lower-grade employee out of his or her job, while maintaining the higher salary for two years. The "bump" triggers a chain reaction down the line, with the lowest-ranking city employees ultimately pushed out the door.

Moreover, the large savings the mayor might hope to gain from those cuts couldn't be realized, in part because of high severance costs, experts say. In fact, it might cost the city money in the short run to fire so many managers.

Both Dixon and Republican mayoral nominee Maurice T. Turner Jr. have made cutting the work force the cornerstone of plans to erase the city's projected $100 million budget deficit this fiscal year.

Dixon, a former utility company vice president, has pledged to fire 2,000 city managers after ordering a management audit by an outside consultant. Turner, a former D.C. police chief, says he would reduce the work force by 6,000 through a hiring freeze and attrition.

But experts on the D.C. personnel system warn that Dixon and Turner will have a tough time turning their campaign pledges into reality.

The main obstacle is the city's labyrinthine personnel manual, which includes the bumping rights provision and allows for employee appeal of firings or reductions in force. Some experts say the District's personnel files are in such disarray that the government might have trouble sustaining layoffs in court or before an administrative panel.

Though there are several thousand D.C. workers who do not enjoy civil service protections and might be easy targets for firing, many of them occupy low-level service delivery positions -- from street sweepers to tax collectors -- that both mayoral nominees have promised not to cut.

Moreover, assuming thousands of workers could be fired, it is doubtful that they could be removed in time to make a serious dent in the projected $100 million deficit for the fiscal year that began Oct. 1, according to budget experts.

At best, they say, a mass firing of 2,000 employees would save $50 million in salaries and benefits, but this ignores millions of dollars in severance pay and unemployment compensation payments that would be incurred by the city in the process.

The inherent difficulties in grappling with the bureaucracy have prompted considerable skepticism among city officials and outside experts about some of the candidates' campaign promises -- particularly Dixon's much-touted pledge to fire 2,000 managers.

"I don't know how she can go about doing that under the current personnel act," said Elijah B. Rogers, an executive of a local engineering firm and a former city administrator.

"There isn't a legal mechanism right now that enables you to go through and selectively reduce the work force in areas where people are not as productive as they should be," said Robert Pohlman, deputy mayor for finance.

A member of the mayoral commission examining the District's fiscal crisis, who declined to be identified, said that while the city bureaucracy is undoubtedly too large, cutting it will take up to five years and likely will have to include reductions in services and programs.

Dixon said in an interview last week that critics such as Pohlman and Rogers "have been there too long that they can't see the forest for the trees." She said she is sticking to her pledge to fire 2,000 city managers -- a move she says would save $50 million to $100 million -- and spur Congress to increase its federal payment to the District.

"I really believe that it can be done," she said.

Dixon appears to have altered part of her platform in response to some of the criticism. In the interview last week, she said she may have to seek temporary authority from the D.C. Council to hold the "bumping rights" in abeyance so that she could selectively fire unproductive managers.

Dixon also said she could avoid problems with the civil service system by firing those without civil service protections. Dixon said she has obtained figures from the District government indicating there are roughly 11,000 workers in that category, meaning that eliminating 2,000 such non-tenured employees would not be a burden.

But city officials have questioned her calculations. According to the D.C. Personnel Office, as of Sept. 8 there were 3,856 non-tenured workers in agencies controlled by the mayor. Of these, about 2,300 were so-called "term" employees, whose contracts with the city government may not expire for up to four years.

Dixon would be unable to fire many of Barry's political appointees. According to information released by the city this week, 94 of the 177 high-level appointees who serve at the pleasure of the mayor were promoted from the civil service, meaning they would have to be offered jobs by Dixon or Turner in January.

Turner has criticized Dixon for proposing to get rid of a large number of city workers, but the Republican's own plan to balance the budget through a hiring freeze and attrition is based on questionable assumptions.

Turner said last week he could eliminate nearly 6,000 jobs and save $200 million within a year through such a proposal -- without raising taxes or cutting programs. "It's going to be painless to the people who are recipients of service in this city," he said.

But Turner's plan appears to be based on what some say are overly optimistic assumptions about the attrition rate in the District government. During fiscal 1989, which ended Sept. 30, fewer than 4,000 people left the city payroll, according to the personnel office.