Gov. Tom Wolf on Tuesday vetoed a dramatic expansion of a program that awards tax credits to businesses that donate to scholarships that help Pennsylvania students pay for private schools.

"It is my job as the leader of this commonwealth to ensure fairness and accountability in our classrooms. House Bill 800 would pour funding into a program that lacks these two critical aspects,” Wolf said in a statement.

Backed by top lawmakers, the bill would have nearly doubled Pennsylvania’s Educational Improvement Tax Credit (EITC) program, adding $100 million in credits.

It also would have allowed automatic increases to the program, and raised the income limit for participating families. Under the bill, a family of four could earn $126,216 a year and be eligible to apply for a scholarship under the program. In 2016-17, 34,400 scholarships were granted to Pennsylvania students through the program, averaging $1,660 each.

In his veto message, Wolf said the proposed expansion “strays from the original stated intent of the program — to lift people out of poverty — and fails to provide any additional accountability or oversight for the tax dollars being expended.”

A fiscal note attached to the bill projected the expansion would cost Pennsylvania’s general fund more than $660 million over five years.

Wolf said that Pennsylvania’s public-education system remains underfunded. “We have public schools that are structurally deteriorating, contaminated by lead, and staffed by teachers who are not appropriately paid and overstretched in their responsibilities. Tackling these challenges, and others, should be our collective priority,” the Democratic governor said in the veto message.

Republican lawmakers, including House Speaker Mike Turzai, said expanding the program would save the state money, because the average scholarship award is far less than what public schools spend per student.

Turzai, the bill’s lead sponsor, said the expansion was needed to satisfy unmet demand for the program.

The bill was also supported by U.S. Sen. Pat Toomey (R., Pa.), who took the unusual step Monday of releasing a letter to Wolf asking him to sign the legislation, calling it “breathtaking” that the governor would consider the bill not good for Pennsylvania. The Pennsylvania Catholic Conference also weighed in, thanking Toomey for contacting Wolf “to ensure that parents continue to have a choice” in their child’s education.

Despite Wolf’s veto, funding for the EITC program is expected to be a part of talks in Harrisburg as the governor and legislature seek to finalize a budget this month. Last year, Wolf signed a budget that included a $25 million increase for the program.