THIS TIME NEXT YEAR, if you want your kid to play high-school basketball, you might have to pay for private-school tuition. And if the marching band is more their thing, start saving for private music lessons.

Aiming to erase a projected $629 million budget shortfall created largely by slashed state support, Philadelphia public-school officials yesterday swung a big ax at the 167,000-student district's budget, proposing drastic changes - such as reopening union contracts and changing state law to decrease support for charter schools - that skeptics say are unlikely to happen.

Yet without the changes, officials threatened, they'll be forced to cut all athletics, instrumental-music programs, bilingual counselors, summer programs and gifted-and-talented programs. Further, class size will balloon by about three kids per class in a district in which some complain that class sizes already are too large.

"This is not a budget that the management of this district endorses," said Michael Masch, the district's chief financial officer. "We do not believe that it is a budget that is good for the children of Philadelphia."

But the state bullied the district into this budget, Masch and Deputy Superintendent Lee Nunery said yesterday at district headquarters.

"Here in Pennsylvania, the governor proposed $1.1 billion in cuts to pre-K-to-12 education - $292 million of those cuts will fall on the School District of Philadelphia," Masch said. "Although we educate just a little over 10 percent of [the state's] students, we are being asked to shoulder more than 25 percent of all of the governor's cuts."

The $629 million gap announced yesterday was far larger than the $465 million that officials estimated just a few weeks ago. Administrators attributed the jump to a deeper analysis and to an increase in non-negotiable expenses, such as contractual salary increases, pension payments and charter schools.

In a morning meeting that wasn't listed on its schedule, the School Reform Commission approved a tentative operating budget of $2.7 billion for next year, down from this year's $3.2 billion budget.

The proposed cuts outraged parents and activists, who accused the district of using students as political pawns and riling up parents to catalyze criticism of Gov. Corbett.

"They're using my child's classroom as their personal political football, and it's not working for me. It's brinkmanship," said Helen Gym, a Center City mother of three who has one child in a district school and two in charter schools.

"The district has lost credibility because it hasn't challenged executive salaries, and it doesn't do competitive bidding on professional-services contracts that cost over $100 million. There's a whole host of things that need to be put on the table, not just essential school services."

Jerry Jordan, president of the Philadelphia Federation of Teachers, blasted the proposed changes but acknowledged that state cuts put the district in an unenviable position.

"There are no good cuts," Jordan said.

Still, cutting early-childhood programs and after-school programs in a poverty-riddled district, when studies show that such initiatives are critical for academic and life success, is "absolutely harmful," Jordan added.

And for those who think that the district is using scare tactics, Jordan said, there's historic precedent: the district made similar cuts as it tried to dig out of a deficit that led to a state takeover a decade ago.

J. Whyatt Mondesire, president of the NAACP's Philadelphia chapter, took the podium during yesterday's news conference to announce a "children's march to save public education" planned for April 26 in Harrisburg.

"The NAACP is not going to sit still and watch this take place," Mondesire said. "Gov. Corbett's policy amounts to attacking public education with a chainsaw. This may not be Libya, but Corbett's budget is as much a threat to the long-term future of the children of Pennsylvania as Col. Gadhafi is to the people of his country."

A Corbett spokeswoman did not immediately return a call for comment.