House school finance negotiators Larry Campbell, left, Clay Aurand and Ed Trimmer huddle during a conference committee meeting Sunday to discuss a combined school funding and income tax overhaul bill.

Topeka ? House and Senate negotiators agreed Sunday to debate a bill that includes both a new school funding formula and an overhaul of the state’s income tax code that would generate more than $500 million a year in new revenue.

That proposal, which the House could debate today, originated from House Speaker Ron Ryckman, R-Olathe. If passed, it would at once resolve two of the three major issues that have kept the Kansas Legislature in session for 107 days. But if it fails, as some expect it will, it could draw the session out even further.

Ryckman gave a stern speech during a Republican caucus meeting just before House members left for the evening, seemingly suggesting that leaders weren’t sure they had the votes lined up to pass the bill.

“Tonight, following days of discussion and listening, there are still way too many unanswered questions, Very important questions,” he said. “The goal post keeps moving. What we cannot do is turn our listening ears off as emotion rises. The exact opposite has to happen. Relationships, negotiating and governing all require honesty, good faith and compromise.”

The tax portion of the bill is identical to one that failed in the Senate, 18-22, on May 22. It would repeal many of the tax cuts that Gov. Sam Brownback championed in 2012, including the exemption for nonwage business income and the so-called “glide path to zero” that was meant to phase out income taxes over time.

It would reinstate a three-tiered income tax structure with the upper tier paying 5.6 percent tax on income over $30,000 for an individual or $60,000 for a couple filing jointly.

It would also impose the state sales tax on some services, such as pet care and pool cleaning.

Overall, it would raise about $491 million for the fiscal year that begins July 1, and $542.6 million the following year.

The Kansas Constitution prohibits the Legislature from enacting bills containing more than one subject. But supporters of the plan say it should pass constitutional muster because all of the money raised in the bill would be earmarked for K-12 education, effectively making the entire state sales tax a tax for schools. The rest of state government would be funded from other revenue sources.

Gov. Sam Brownback has said previously that he would veto any three-tiered tax plan, which means the bill would need to pass both chambers with veto-proof margins. But that appeared unlikely because the two Democrats on the conference committee, Sen. Anthony Hensley, of Topeka, and Rep. Ed Trimmer, of Winfield, both refused to sign the report, which means it’s unlikely the bill will receive any votes from Democrats.

“This moves it into the theater of the absurd,” Sen. Laura Kelly, D-Topeka, said after hearing the proposal.

Lawrence Rep. Tom Sloan, a moderate Republican, said he thought the school funding portion of the bill could pass on its own. But he said he could not support the tax provision because it doesn’t provide enough money to restore cuts made last year to higher education or to make investments in other state facilities such as Osawatomie State Hospital.

Also, Rep. Melissa Rooker, another moderate Republican from Fairway, said she was uncomfortable putting both a tax plan and a school finance plan into a single bill, and that the two issues needed to be separated.

The school finance portion phases in over two years a $280 million increase in annual spending for public schools. But it also expands a kind of voucher system that provides a 70 percent tax credit for contributions to scholarship funds that enable students from the state’s lowest-performing public schools to attend private or parochial schools.

If the plan were to become law, the Lawrence School District would see an increase of about $3.5 million in the upcoming school year, according to Kansas State Department of Education estimates.

The funding portion of the bill largely reflects the plan that the House passed earlier. The Kansas State Department of Education estimated that the Lawrence School District would receive about $3.5 million more under that plan than it is receiving this year.

The Eudora School District would see an increase of about $684,000, and the Baldwin City district would see an increase of nearly $495,000.