Philadelphia's public schools could lose $40 million in state funding next year if a school-voucher bill being considered by state lawmakers is approved, School District officials said at a hearing Tuesday.

The figure assumes that 10 percent of the students who would be eligible for the vouchers would use them.

Such a funding loss would seriously hurt a district already facing a gap of $400 million to $500 million in a $3 billion budget, said Deputy Superintendent Leroy Nunery, who testified before the General Assembly's House Democratic Policy Committee at the Independence Visitor Center.

Besides the potential voucher loss, Nunery said, the district anticipates losing $300 million in federal funding.

According to Nunery, $40 million could pay for all the School District's nurses and interscholastic athletic programs, and 20 percent of its librarians.

The hearing came as lawmakers in Harrisburg continue to debate a bill to create a voucher program, which would let students from low-income families attend private or parochial schools with the aid of government-funded vouchers. The Corbett administration has expressed support for school-choice programs in general, although it has not declared its support for the bill being discussed. Senate Bill 1, which has support from Republicans and Democrats, is expected to be voted on by the Senate Education Committee next month.

Under the legislation, the first two years of the program would allow low-income students in the 144 worst-performing public schools in Pennsylvania (excluding charter schools) to apply for vouchers. Ninety-one of those schools are in Philadelphia, and 51,000 students would be eligible for vouchers the first year, Nunery said; 23 percent of the state's low-income students are educated by Philadelphia.

In the third year of the voucher program, low-income students anywhere in the state could apply for vouchers.

Nunery and the School District's chief financial officer, Michael Masch, said the district could be left with funding equivalent to what it received in 2007.

"If tens of millions of dollars of additional funding are diverted at the same time . . . that will make it enormously difficult for us to maintain the momentum of the last eight years," said Nunery, who urged lawmakers to change the legislation so Philadelphia schools would not lose funding for every student who took advantage of the voucher program.

The amounts of the vouchers would vary from district to district, depending on the amount of state aid sent to the district; in Philadelphia, the vouchers would work out to about $7,900 per student.

Masch said the district's costs would not decrease proportionately when students left through the voucher program. If three students left one school, for example, the district could not get rid of a teacher, a principal or a librarian, and would still have to pay to heat the school building, he said.

Proponents argue that vouchers give parents more options for their children's education and spur public schools to improve by creating competition. Opponents say vouchers may hurt districts that lose students and funding.

Lawmakers wondered how much choice the voucher program would give parents if private and parochial schools could choose which students they accept.

"I don't see anything in here that guarantees that a kid with a voucher gets the opportunity," said Rep. James R. Roebuck Jr. (D., Phila.).

Joe Watkins, chairman of Students First, which advocates for school choice, responded that for parents desperate to send their children to better schools, vouchers represent hope.

"People are so desperate in our cities and towns around the commonwealth that even the hope, the possibility, of doing better than they're doing now is good enough," Watkins said.

Mary Rochford, superintendent of the Roman Catholic Archdiocese of Philadelphia, which has lost thousands of students with the rise of charter schools, said the archdiocese had 13,748 empty seats in Philadelphia and 19,135 empty seats in the suburban counties.

Witnesses and lawmakers expressed concerns that the voucher programs would hurt the public schools, instead of helping them.

"This is a bill that would draw precious resources out of our public schools," said Lawrence Feinberg, a Haverford Township school district board member who cochairs the Keystone State Education Coalition, a group of school board members and administrators. "The problem I have with this bill is it just says, let the building burn. There's nothing in this bill that helps public education."

But voucher proponents say opponents complicate a simple issue.

"It's not about all these ancillary issues that everyone keeps raising," said Otto Banks, executive director of the REACH Alliance and Foundation, a pro-school voucher organization. "It's about the children. Many of these children are without hopes, without dreams, without aspirations . . . [This bill] is that opportunity."

Contact staff writer Adrienne Lu at 215-854-2624 or alu@phillynews.com.