As if an unwieldy budget and soaring street violence weren't making Mayor Marion Barry's life tough enough, yesterday he got his report card from the city's largest parent advocacy group. It was not pretty.

Barry picked up three As, but the card was littered with stern comments, plenty of Cs and Ds and -- gulp -- 10 Fs.

"Despite progress in several subjects last year, your schools have fallen far behind other local school systems in teacher and principal salaries," the comments said. "Immediate action is required here."

The card, signed "John and Mary D.C. Public," is an annual exercise by Parents United, designed to grade the mayor on the classroom services recommended in his proposed school budget. Of course, the report card also is designed to boost support for the school board's $492 million budget plan, which Barry proposes to cut by $44 million.

Barry "was not surprised, but he's a little disappointed in the grades because education remains one of his highest priorities," said his press secretary, John C. White. The mayor contends that his budget is sufficient to maintain recent school improvements.

The parents who grade Barry base their scores on surveys of staff levels, building conditions and salaries in District and suburban school systems. As usual, the D.C. schools fare poorly in such comparisons.

In the District, starting principals are paid $10,500 less than the median starting pay in surrounding suburbs. Grade on principals' pay: F. Same story, though with a narrower gap, for teachers' pay.

"The mayor and almost every elected official in town is committed to comparable pay for District teachers," said Rod Boggs, counsel to Parents United. "We're sure the mayor would not go back on his commitment to the voters."

Parents United also criticized the mayor and the school board on their failure to improve athletics and other extracurricular programs. Grade: F.

"The facilities and resources for these activities in the District are just pitiable," said Mary Levy, budget analyst for the parents group. "The head football coach in a D.C. high school gets less pay than a cheerleading coach in Montgomery County. We have high school newspapers that get put out four times a year because that's all the money the children could raise by selling doughnuts."

Many of the mayor's worst grades came in subjects related to the physical conditions of city schools. Only half of the city's junior high schools have science labs. Only half of the high schools have modern labs. And school libraries have considerably fewer books than those in the suburbs, the parents' survey found.

To accentuate the need for more money for repairs and supplies, Parents United released its report card at a news conference in a stultifyingly overheated classroom at Langley Junior High School in Northeast. One wall of the classroom in the 65-year-old building was crumbling; much of the paint had chipped off because of a leaky roof.

The D.C. system's only good grades came in the availability of programs for very young children, including an all-day kindergarten and a preschool program for 4-year-olds.

"That's unusual," Levy said. "They don't even do that in the suburbs."

The low grades seemed a low blow to school board member Angie Corley (Ward 5). "Our schools are very, very old," she said. "Very little has been done in improving our schools. But these grades are so low it's depressing. It's so low that it might have a negative effect. We're trying to work out a good budget."

Parents United is not alone in its maneuvering in the final hours before tonight's D.C. Council hearing on the school budget.

A report by council budget director Arthur Blitzstein argues that there is little reason to give the school system more money because the system routinely fails to spend city money as the school board promises.

The report says the school system has consistently underspent its budget for building repairs and teachers salaries, in the latter case by $8.3 million last year. That angers council members who acceded last year to an urgent school board plea for money to hire more teachers to provide smaller classes. Much of that money appears to have been spent on supplies, the report said.

The school board wants the council to allocate new money to hire hundreds of new teachers and further reduce class size, but the system's past spending "does not give much promise that . . . the funds will end up being spent primarily to hire teachers," Blitzstein said.

School administrators say the budget figures are misleading. Because of the difficulty in recruiting teachers to the District, the system has instead hired part-time and uncertified teachers, whose pay comes from nonpersonnel accounts.