Gov. Corbett, who has pushed hard for a school-voucher program, achieved much of that goal Saturday night through the expansion of a corporate tax credit that for the first time will pay for public school students to attend private schools.

As part of the budget deal concluded just before midnight, the legislature broadened the Educational Improvement Tax Credit program (EITC), adding $50 million in tax breaks to businesses that donate money for scholarships to students in the state's lowest-performing schools.

The new tax credit applies only to students in the attendence area of the lowest-performing 15 percent of public schools, more than one-third of which are in Philadelphia.

The possible impact on the city's struggling Catholic schools was reflected in a statement from Archbishop Charles J. Chaput, who praised the legislation as "a strong first step toward what we need to help secure Catholic education in the Archdiocese of Philadelphia and to provide families . . . with real choices in how to best educate their children."

The budget provides for corporate donations to pay up to $8,500 in tuition for the students to attend private schools. Special-education students can get up to $15,000 in tuition.

Preference is given to low-income students; those in a family of four earning less than $41,348 would get priority, for example. It also gives preference to Philadelphia School District students, as well as students from Delaware County's Chester Upland District and three other districts - Harrisburg, York City and Duquesne - about to be declared distressed under new state legislation.

The legislation also increased funding for the original EITC program, adopted in 2001, which gives corporate tax breaks to fund tuition only for students already in private schools, by $25 million.

The existing tax credit program will expand from $75 million to $100 million this fall. Of that amount, $60 million will go for private school scholarships, $30 million for educational organizations that offer special programs for schools, and $10 million for pre-kindergarten private school programs.

Legislators found it difficult during the last 18 months, since Corbett began advocating vouchers, to spend money directly from the state education budget for the program. They apparently found it more palatable to instead expand corporate tax credits for the same purpose.

Lawrence Feinberg, a voucher opponent who is a school board member in Haverford, Delaware County, and co-chair of the Keystone State Education Coalition, said the bill's passage marked "a sad day."

The program, he said, diverts "money that should have been going into the general fund for use in the state budget" and "uses these tax dollars to fund private and religious schools."

No list of the lowest-performing 15 percent of schools has been released, but an Inquirer analysis of state school test scores for 2011 showed about 160 Philadelphia public schools on the list. That is more than half the schools in the Philadelphia district.

Eleven other Philadelphia-area school districts have at least one school in the bottom 15 percent: Bristol Borough, Bristol Township, Chester Upland, Chichester, Coatesville, Norristown, Octorara, Pottstown, Southeast Delco, Upper Darby and William Penn.

If the scholarship slots are not filled by lower-income students, those with a family income of up to $72,000 for a family with one dependent child will be eligible.

A company could get up to $400,000 a year in tax credits for making scholarship donations, with that amount increasing in future years.

Eligible income levels for recipients in the existing program will be the same as those for the new program, as will the amount of tax credits each corporation can claim.