BEFORE he left as the chairman of the House Appropriations Subcommittee on the District, Rep. Charles Wilson of Texas said he was indifferent to the city's budget problems because the D.C. government has too many employees. Until the city reduced the number, Mr. Wilson said, Congress could not justify helping it out of its financial crisis. This charge has been repeated year in and year out by each chairman of the subcommittee. Is it true?

Local officials argue that the District has more employees because the government here performs state and county functions as well as those of a city government. That argument has some merit. But even considering that, the District has 708.4 employees for each 10,000 of population. The average in other jurisdictions, according to the Census Bureau, is 485.3 state, county and municipal employees per 10,000.

District officials say it is misleading to overemphasize the ratio of government workers to the size of the population. The statistic they prefer is the ratio of workers to the number of people directly served. The large number of poor people here, about one-quarter of the population, according to District officials, requires a large force of workers to serve it.

But not only members of Congress suspect there are too many city government employees. The Barry administration's own "transitional task force" said early on that the city bureaucracy seemed overladen. There have long been suspicions that lovers, cousins and aunts and uncles are hidden on city payrolls in do-nothing jobs. Now that the city is in serious financial trouble, and is asking Congress for the full possible supplement to the federal payment to the city, there is the need to settle this matter.

One way to quiet whispers would be to start zero-based budgeting for all District agencies: require all District department heads to list their departments' basic functions and the minimum numbers of employees necessary to do the jobs. Any added jobs would have separate price tags. This system would force the mayor and council to weigh the cost of the job versus the value of having it done. For example, every police department employee above a minimum number of patrolmen and supervisors would be pinpointed, and approved or rejected by the mayor and council.

The zero-based system also would allow city officials to see how many employees could be cut without seriously damaging city services. Currently, the mayor plans to cut 1,000 employees, while business leaders and council member John Wilson would like the mayor to cut about 2,500. But neither the mayor nor Mr. Wilson knows how many unnecessary employees there are in the Distrct government. The zero-based system would give them some idea.