HARRISBURG — Republicans in control of Pennsylvania’s Legislature scrambled Tuesday to finish writing a host of budget- and education-related bills to get them to fellow Republican Gov. Tom Corbett before the new fiscal year starts Sunday.

That meant significant changes in state policy — even the particulars of a $1.7 billion, 25-year tax break being sought by Corbett for a would-be petrochemical industry — were still under wraps, being worked on behind closed doors by Republicans just four days before they hope to make the provisions law.

Debate on the floor of the House of Representatives could begin today on Republicans’ $27.7 billion spending plan for the 2012-13 fiscal year that begins Sunday, said House Appropriations Committee Chairman Bill Adolph, R-Delaware.

Republicans made more details about the plan public on Tuesday afternoon, although Democrats questioned whether changes were still possible as Republicans tried to resolve disagreements behind closed doors.

“It sounds like there’s still some questions, even among the Republicans,” said House Democratic spokesman Bill Patton.

One such disagreement is over the Corbett administration’s pitch to create one block grant program to absorb seven different pots of aid for county-administered services for the mentally ill and disabled, neglected or abused children, homeless and drug and alcohol addicts.

A House floor vote on the general appropriations bill is not possible until Thursday, unless House members vote to suspend internal rules. Both the House and Senate must still sign off on the couple dozen budget-related bills that traditionally make up the budget every year.

Also, four pieces of education-related legislation sought by Corbett — expanding a tax-credit program that helps children transfer to private schools or better public ones, establishing a process for assisting financially ailing school districts, placing the regulation of charter schools under a statewide board and broadening teacher evaluations to include objective measurements — were still being drafted Tuesday.

Senate Education Committee Chairman Jeff Piccola, R-Dauphin, downplayed questions about the transparency of producing legislation from behind closed doors within a couple days of it being signed into law. The broad themes of the bills are already in existing bills, if not the finer details, he said.

“You’re not going to see anything brand-new emerge,” Piccola said.

In terms of the budget, spending for health care, pensions and debt would rise in a no-new-taxes measure that otherwise would increase spending by about 1.5 percent. Tax collections would increase by more than 3 percent.

Public schools would see a slight increase, although that extra amount — about $50 million — would be set aside for a yet-to-be-identified group of school districts nearing financial collapse, Adolph said.

Also, 18 state-supported universities would get the same amount as last year. Taxpayer support for tuition grants to college students would shrink, but the overall amount would remain the same.