People seeking to file or be interviewed in the District of Columbia for unemployment compensation often must wait four hours or longer because the office does not employ enough people, the D.C. Department of Labor acknowledged yesterday. It blamed the federal government.

The complaint about a staff shortage in the department's unemployment benefits division was voiced by its assistant chief, Charles W. Knight, to Mayor Marion Barry at a meeting on Thursday.

Knight said the staff was short by 31 employes, and that he had been asking for help for 10 months. Yesterday he told a reporter that the staff, authorized at 132, has fallen to 101.

Many of the 31 persons would be assigned to jobs of accepting and screening applications or interviewing applicants about disputed information, Knight said.

Because of the shortage, Knight said he himself is now doing tasks normally assigned to three persons.

Lorenzo M. White, acting director of the department, and other departmental officials, while not directly confirming the numbers cited by Knight, agreed that the compensation program is understaffed.

The full $4.9 million annual budget for administering the D.C. unemployment program is supplied by the U.s. d/epartment of Labor, which reduced the number of authorized workers as unemployment declined, the officials said. As a result, employes who left the agency were not replaced.

The D.C. department, citing unique governmental and employment patterns in this area, has appealed to the federal agency for more personnel.

P. J. Columbro, deputy regional administrator of the U.S. Department of Labor's Employment and Training Administration, said the D.C. request is being reviewed with a decision likely soon.

William V. Wilkerson, the D.C. official who directly oversees the compensation program, said the current interview crunch resulted from an increased workload caused by cold weather, after-Christmas layoffs, a large turnover in congressional staffs and decisions by many newly unemployed persons to delay their applications until the start of 1979 to qualify for increased weekly benefits.

In December, the department processed 59,462 new or renewed claims. In January, the number spurted to 73,812.

Several of those waiting for interviews yesterday were sympathetic to the problems cited by the officials. "They need help," said a construction manager, who arrived at the office at Sixth Street and Pennsylvania Avenue NW at 12:30 p.m. and was still waiting for an interview at 3 p.m.

"Man, I got nothing else to do, and it's warm in here," said another.