Prince George's school officials this week pleaded for public support in their coming battle with the county executive and County Council over funding for next year's budget.

Speaking to an audience at Largo Senior High School composed mostly of school employes, principals and administrators, Assistant Superintendent Elliott B. Robertson asked the public to help fight for the $336,554,972 the school system says it needs next year.

Almost all of the speakers at the public hearing said the budget was barely adequate--or not enough.

Robertson presented the superintendent's request as a fat-free survival budget. "There doesn't seem to be enough money to go around," he warned his audience. "We are going to plead for your help."

The proposed budget is 9.1 percent higher than this year's budget. But because state and federal contributions have declined and less money is left over from last year than in the past, the county government would have to pay about 20 percent more to meet it.

The budget includes a $10.1 million increase in salaries, a $3.1 million increase for special education programs, which have suffered from cuts in federal funds, and $2.1 million to buy 111 new school buses. A new Science and Technology Center is set to open in Oxon Hill next September, and more money is targeted for advanced placement courses. Cutbacks include 328 staff members, mostly through attrition.

Diana McCusker, president of the County Council of PTAs, pleaded with the audience to go to the County Council and County Executive Lawrence J. Hogan "and request adequate funding."

Donald Forrester, president of the Associaton of School Administrators, called the budget a "reasonable level of projected funding."

Board member Catherine M. Burch, speaking after the hearing, said conflict with Hogan is inevitable.

Burch said she will contact all the PTA organizations in her Silver Spring area and try to meet with them personally. She said she will encourage PTA members to write letters of support for the proposed budget.

School Board Chairman Doris A. Eugene was told by Hogan in a letter last week that "The school system knows that its request cannot possibly be funded within the TRIM limit without decimating other vital county services." TRIM restricts property tax revenues in the county to the 1979 level of $144 million.

Hogan said the request is "particularly astounding when viewed in the context of a 4.3 percent decline in student enrollment."

But Eugene was defiant on Monday night. She said Hogan's argument that fewer children should mean lower costs was "not playing square with the public." He had refused to consider that inflation and overhead costs necessitate budget increases despite school closings and falling enrollment, she said.

In recent years, Hogan has complained that every budget proposed by the superintendent is too large. The school board always has approved the superintendent's budget, more or less intact, and Hogan has cut it before passing it on to the County Council. The council then has restored about a third of the funds removed by the executive.

"I don't think there's any significant difference" this year, Robertson said after the hearing. "The words are different, but the music is the same."

A second hearing was held last night, and a final hearing is scheduled for 7:30 p.m. Monday at the Southern Area Administrative Office in Oxon Hill. The board then will complete the budget in six work sessions, vote on it and send it to Hogan.