Spending for Fairfax County schools and government should be cut by up to 2 percent in the budget year that begins Sunday, Board Chairman Audrey Moore proposed yesterday after predicting a $65 million county deficit in the following fiscal year.

The cuts would have to be approved by the School Board and the County Board. Moore also said she would ask the boards to hold spending increases to 4 percent in the following budget year. County spending increased 8 percent and school spending was up 10 percent in the current budget year.

Moore said her proposals, which immediately drew fire from some of her board colleagues and school advocates, are needed because of a projected decline in tax revenue.

If county and school spending continue increasing at their current pace, while property tax receipts go down because assessments are flattening out and sales tax revenue decline, Moore said the deficit would reach $65 million in the budget year that begins in July 1991.

She said cutting 1 to 2 percent could create a reserve of $12 million to $24 million "for a down payment on what could be a large 1992 budget gap." She said she would ask the boards to dedicate any funds left over when the current fiscal year ends this Saturday to the deficit fund.

Moore said she would not yet suggest what programs might be cut. She did not address whether employees might be laid off, but noted that personnel costs make up a large part of county spending.

Worries about spending, taxes and deficits are not unique to Fairfax County. Local governments throughout the Washington area are grappling with a host of unpleasant budget realities.

The District government is facing similar financial problems because of the slowdown in the regional economy and the rapidly escalating costs of human services and public safety programs. Officials have projected that the city faces a $95 million budget deficit for the fiscal year ending in September.

On Monday, the District announced a fiscal rescue package that includes four-day furloughs for city employees and cuts in AIDS education, job training, mental health service and other programs.

Montgomery County does not face a deficit. In fact, spending will be up 9 percent in the new fiscal year even as higher assessed valuations allowed officials to cut the property tax rate. But the Montgomery County Council cut budget requests from its departments, mostly in response to complaints from anti-tax groups.

Fairfax County does not face a deficit this year either and was able to approve an eight-cent cut in the real estate tax rate. The spending cutbacks proposed by Moore for the fiscal year beginning on Sunday would be aimed at cushioning a deficit expected a year hence.

With one of the highest standards of living in the nation, Washington area residents demand top-flight government services. Flush with revenue from new development, local governments in the last decade expanded those services but are having trouble paying for them now that the economy has gone soft.

"The good times have rolled, and it has meant substantial increases" in spending for such areas as teachers' pay, transportation and human services, Moore said at a luncheon meeting of the Springfield Rotary Club.

Now, she said, "I'm trying to set the tone for where we have to go . . . . I believe that the difficulties we faced this year will seem tame in light of the budget and tax challenges that lie ahead."

It was unclear yesterday whether Moore could muster the votes to enact her proposals, but she clearly faces an uphill battle, especially in trying to cut school spending. School advocates are the most powerful interest group in the county and, with board elections in 1991, probably will flex considerable muscle in opposing Moore's proposals.

Moore, who voted against the $1.4 billion fiscal 1991 budget when it was approved in May, told few colleagues about her proposals before announcing them publicly, leading some of them to question her leadership style.

Supervisor Thomas M. Davis III (R-Mason), who is considering challenging Moore for the chairman's post next year, called her ideas "the typical hysteria to any issue that comes across the bow."

"I see she finally realizes her policies of the last three years are putting the county to the brink of financial ruin, and now she's trying to backpedal and blame everybody else," Davis said.

Walter J. Mika Jr., president of the 6,800-member Fairfax Education Association that supported Moore in 1987, said her latest proposal indicated she was "shooting loose cannons" as part of her 1991 reelection campaign. "It's going to be awfully hard for our people not to see Tom Davis as a white knight," he said.

Marlene Blum, vice president of the Fairfax Parent-Teacher Associations, said the county risks shortchanging its schools. "We are not going to stand by and let that happen to our school system," she said. "The good news is, this is just Mrs. Moore speaking and not the rest of the board."

School Superintendent Robert R. Spillane, School Board Chairman Kohann H. Whitney, Supervisor Lilla Richards (D-Dranesville) and County Board Vice Chairman Martha V. Pennino (D-Centreville) reserved judgment on Moore's proposals, saying they wanted specifics.

Supervisor Joseph Alexander (D-Lee) said Moore had not discussed budget cuts or limits with him, adding, "I don't think we can trim 1 or 2 percent as far as the county is concerned . . . but I think there's plenty of room for a 1 or 2 percent cut on the school side."

County Executive J. Hamilton Lambert said Moore's deficit projections were accurate, "given certain assumptions." He noted that sales tax receipts were down, and said he expects "significant drops" in revenue from personal property taxes and real estate taxes.

Moore said her proposals were not influenced by the tax revolt in the county, but said she will strongly oppose any increase in taxes to make up for declining revenue.

"I believe that these . . . actions are both prudent and necessary to ensure that in 1992 Fairfax County lives within its means," she said.

Staff writer Michael Abramowitz contributed to this report.