NASHVILLE (AP) — Democratic lawmakers who want to use surplus state revenues to halt tuition increases and make deeper cuts to the sales tax on groceries called on Republican Gov. Bill Haslam Wednesday to convene a special session to discuss the ideas.

The legislators said at a news conference that they'd like the session to be in August, possibly before students return to school.

"We believe we could meet the needs of the higher education institutions, while at the same time essentially holding the students harmless for this next year for increased tuition," said Senate Democratic Caucus Chairman Low Finney of Jackson.

Lawmakers said the state has about $225 million in excess revenues that could be used to help students.

Based on numbers provided by the Tennessee Board of Regents and the University of Tennessee system, Democrats said $78 million of the excess revenue would cover all proposed tuition increases at state colleges and universities.

The state Board of Regents oversees six universities, 13 community colleges and 27 technology centers. Its finance committee recommended tuition hikes that will be presented to the full board later this month. East Tennessee State University has the potentially highest increase at 7.2 percent and Austin Peay, the lowest at 3.4 percent.

The university system has an enrollment of about 50,000 students at campuses in Knoxville, Chattanooga and Martin; the Health Science Center in Memphis; state Institutes of Agriculture and Public Service; and the Space Institute in Tullahoma.

On Thursday, the UT Board of Trustees will vote on tuition hikes that range from 8 percent at the Knoxville campus to 4 percent at the Health Science Center.

Senate Minority Leader Jim Kyle of Memphis said continuing to increase students' tuition is no different than taxing them.

"It is a tax increase on people who are trying to improve their lives, and improve Tennessee by getting a better education," he said.

On Wednesday, the finance committee of the UT Board of Trustees approved a new tuition model that would start in 2012 and hopefully benefit students.

Under the proposal, which will also go before the full board on Thursday, students would have "the expectation of tuition increases of 3 percent for the next three years. After four years, they pay the prevailing rate," according to UT officials.

UT President Joe DiPietro said the tuition increases are needed to help give students the best education possible.

"Revenues from increased tuition levels will go toward enhancing the educational experience for students, such as improving infrastructure, reducing bottleneck courses, and providing more advising and other support," he said.

Also Wednesday, Democratic lawmakers said they want to use the state surplus to drop the sales tax on groceries below 5.25 percent. Haslam included funding in his budget to reduce the sales tax from 5.5 percent.

"We can provide Tennesseans four times the amount of tax relief in a matter of days," said Sen. Tim Barnes of Clarksville. "It would mean a lot to people in my district who are barely making ends meet as it is."

Haslam spokesman David Smith said the governor is committed to maintaining the state's balanced budget and addressing cost concerns at higher education institutions, but stopped short of saying a special session is needed.

"We want to be sure we have a complete picture of what our budget commitments will look like before we interrupt the budget process and start spending funds in an ad hoc way," he said. "Regarding higher education, the governor has said and continues to believe we need to focus on higher education in Tennessee, and examining the cost structure is certainly part of that process. That shouldn't be done from a quick-fix perspective."