The Philadelphia School Reform Commission adopted a $2.8 billion "interim" budget Tuesday night, formally endorsing deep cuts but signaling that it might be able to roll back some of the most painful ones.

"Many of the critical building blocks of the school district's budget are still uncertain," chief financial officer Michael Masch told the SRC at a dramatic special meeting.

But unless talks in City Hall, Harrisburg, and elsewhere yield new funding, full-day kindergarten is gone, as is most transportation. There will be 3,409 fewer positions next year, including 1,158 fewer teachers, and cuts to early-childhood education, individual school budgets, nurses, counselors, the arts, and more.

District officials said a huge drop in proposed state aid and the end of federal stimulus money forced them to close a $629 million gap in a budget that Superintendent Arlene C. Ackerman said would require "sacrifice on everyone's part."

The SRC also warned that if its five unions did not come up with $75 million in concessions by June 30, Ackerman would recommend that the commission vote to cancel their contracts - an unusual power given by the state takeover law but not used in a decade.

Jerry Jordan, president of the Philadelphia Federation of Teachers - the district's largest union - said he had not renegotiated and would not do so. He said the PFT negotiated a contract in good faith and already gave concessions.

"The School Reform Commission and the superintendent have really lost their credibility with their actions tonight," Jordan said in an interview. "This gap wasn't created by us, and now they're asking us to bear the burden."

Asked if he believed the district was prepared to cancel the teachers' contract, Jordan said the union would "deal with that when we have to."

Jordan also objected to a resolution passed Tuesday night that would exempt teachers at Promise Academies - district-run turnaround schools - from layoffs. He has vowed to fight that measure in court.

The budget passed 3-1. Commissioner Joseph Dworetzky said he supported the budget only "reluctantly."

Commissioner Johnny Irizarry, who asked several questions about cuts to alternative-school providers, voted no.

"I just felt there were too many unanswered questions," Irizarry said after the meeting. "I didn't agree with some of the cuts."

Legally, the district must adopt a spending plan by the last day of May, but Masch said he fully expected to ask the SRC to adopt an amended budget - restoring some funding - over the summer.

The SRC got an earful from dozens of speakers at the three-hour meeting.

City Councilman Bill Green, a frequent district critic, said he hoped to help find new money for the district, but upbraided officials for their approach to cuts.

"Stop the fearmongering, adopt a responsible budget, and treat your partners at the city and state like adults," Green said. "Restore things that are proven, like full-day kindergarten and early-childhood education, then come make the case for things that aren't yet proven."

Parent Rebecca Poyourow said she was "concerned - to put it mildly - with what seems like a fundamental lack of oversight and appropriate policy-setting on the part of the SRC and the Philadelphia School District when it comes to stewardship of the funds the district does receive."

Green, Poyourow, and others suggested the district's priorities were out of order - funding an 18-day summer school at a price tag of about $23 million, but cutting transportation and full-day kindergarten, for instance, and paying big salaries to central administrators, but cutting jobs and counting on givebacks from teachers.

Poyourow, whose older son is a first grader at Cook-Wissahickon Elementary in Roxborough, is one of hundreds of parents who have mobilized to lobby legislators for more funding.

"Our message to the members of the SRC and to the district is that we believe in our schools, and we will fight for public education," she said, "but you have got to put this house in order."

Several people also questioned the district's decision to continue to funnel extra money into turnaround schools while cutting principals' discretionary budgets at individual schools by 29 percent.

Multiple speakers also urged the district not to proceed with a plan to let go most providers of alternative schools for students who have dropped out or are at risk of doing so. The district has said it would run those programs in-house, serving more students for less money - instead of paying $20 million, it will spend $8.7 million, officials said.

Student Joandaly Chavez said El Centro, the accelerated academy she attends, "is my high school, my pride, my integrity, and, most important, my education." She and others said they'd had bad experiences at district schools and were successful only under providers such as Big Picture Philadelphia, which runs El Centro, and Camelot.

Associate Superintendent Penny Nixon said students in district-run alternative schools would not lose services and would have individualized learning plans to help them do well.

Special-education advocates also raised fears about cuts to those programs. The district will trim 5 percent, or about $10.7 million, from its special-education budget.

But many services are legally mandated and cannot be cut, advocates pointed out.

District staff said that no service required by law would be lost and that they would monitor the situation closely over the summer.

Restoring full-day kindergarten is the first priority, Ackerman and other officials agreed, but it appears that at least a partial restoration to transportation cuts is closest to happening.

"We are hopeful that there will be a positive outcome," Masch said of talks with SEPTA and others to restore transportation funds, "but we are not yet in a position to say that for sure."

Contact staff writer Kristen Graham at 215-854-5146 or kgraham@phillynews.com.