The Fairfax County Council of PTAs voted last night to oppose any ceiling on the county education budget set in advance by the School Board and County Board of Supervisors.

The resolution was approved on a voice vote without audible dissent from among the 250 people in the audience.

The vote was the first of its kind for the council, which represents 151 Fairfax PTA chapters. Supporters said the vote reflects the willingness of the PTA to take on county politicians on the budget issue during relatively good economic times.

On Monday, the supervisors approved a resolution suggesting that the next school budget, for the fiscal year beginning next July, be set using three guidelines: inflation, county population increase and growth in school enrollment. The School Board will discuss that resolution at its meeting Thursday and is expected to vote on it in November.

The resolution approved by the supervisors does not specify a budget figure. But Pat Hanlon, budget chairman for the PTA, told last night's meeting the supervisors were told that under the resolution the School Board would be "directed to develop" a budget based on population, inflation and enrollment -- in effect, he said, a ceiling. But Hanlon said schools should receive money from the county "to the extent to which they need it." The supervisors' proposed resolution, he said, keeps the "pie divided pretty much as it is."

Board Chairman John F. Herrity, who attended the PTA meeting to appeal for votes on a county road bond issue next month, defended the resolution as a vote for fiscal responsibility.

"It lays the foundation not only for a sound educational policy but also a sound fiscal policy," Herrity said. He said the resolution is only a guideline, but under questioning he conceded that if the school superintendent proposed a 20 percent budget increase it would "violate the spirit of the resolution."

The School Board and county supervisors began setting an education budget ceiling in advance of actual budget hearings four years ago during the national economic recession. In past years a specific percentage increase was pegged to increases in overall county revenue.

But opponents of a budget ceiling argue that economic times are better now and the schools should not be shackled by an arbitrary limit.

School Board Chairman Mary E. Collier said before last night's vote that past budget ceilings have been set at reasonable levels and are not inherently bad.

The supervisors hold the purse strings for all county spending, including the budget for the school system. But the superintendent and School Board decide exactly how the money will be spent.