More than 900 San Francisco schoolteachers, administrators and other staff members - nearly twice that of last year - are in line to receive layoff notices in the next few weeks as district officials prepare to cover a worst-case budget scenario next year.

The school board is expected to vote tonight to authorize the pink slips, a decision required by state law to meet a March 15 deadline for notifying teachers and administrators that they might not have a job next year.

District officials said the list is long given the mind-boggling $113 million budget shortfall expected over the next two years, a deficit requiring huge cuts to staffing and programs. It includes full-time and part-time employees representing nearly 800 full-time teaching and administrative positions for the most part. It doesn't include such workers as clerks or school secretaries, who don't have to be notified by the deadline.

Many pink slips sent out by March 15 could be rescinded during spring, as was the case in prior years, but district officials won't know how many people will be laid off for months as the financial situation becomes clearer.

As it stands now, the number of pink slips expected to hit mailboxes in early March is "overwhelming," said Dennis Kelly, president of the United Educators of San Francisco.

On the list are 318 teachers, about 10 percent of those currently employed in district classrooms.

"It is literally a decimation of the teaching force," Kelly said.

Those with the lowest seniority will be the first to be cut, which means struggling schools that typically have less-experienced teachers will feel the layoffs the hardest.

The district is counting on several labor unions, including Kelly's, to make significant contract concessions in pay, benefits and even class sizes to avoid at least some of the layoffs. An early retirement incentive of $4,300 for eligible teachers is also on the table, something that officials hope would eliminate positions through attrition.

Superintendent Carlos Garcia has laid out a plan to address the $113 million shortfall, including raising K-3 class sizes from 22 to 25, severely cutting summer school, instituting districtwide furloughs and cutting busing services. Some of those things require the approval of unions.

Union wants proof

The teachers union has requested that district officials demonstrate the financial need for the layoffs and other cuts to teacher benefits before agreeing to concessions.

The district's operating budget is about $400 million annually. It faces the huge shortfall because of state cuts to education over the past few years combined with the state's decision not to provide cost-of-living increases last year, this year and probably even next year based on the governor's proposed budget.

Virtually every district in California is struggling with similar cuts and layoffs.

Board member Jill Wynns has sat through layoffs several times during her 17 years on the board. It's an arcane process requiring districts to send out cautionary notices - just-in-case pink slips until the state budget shakes out, she said.

"Many of the layoffs have been rescinded within a few weeks," she said. "This year, it's going to be different."

Fewer city dollars

Last year, district officials mailed out about 500 layoff notices to teachers and administrators to help cover an expected $29 million shortfall. All the pink slips were rescinded after City Hall agreed to give the district about $24 million from the city's rainy day fund.

Next year, the district is counting on only about $6 million from those city reserves.

At Visitacion Valley Middle School, Principal Jim Dierke, a 39-year district veteran, is expecting a pink slip in his mailbox. He would be one of dozens of administrators to get one because their typically renewed, three-year contracts are up. But his thoughts were with the energetic, young teachers just starting their careers, teacher aides, counselors, librarians and others who could lose their jobs.

"This is the worst it's ever been," said Dierke, adding the loss of staff has a direct impact on struggling students. "Every adult is worth a pot of gold, so it's not a good thing."