State lawmakers are scheduled to convene Sept. 5 to determine the support for proposals that would change the state income tax and rework funding for transit projects in Salt Lake County.

If there's enough legislative enthusiasm, Gov. Jon Huntsman Jr. is expected to call a special session Sept. 20 to move the measures forward. That's "very likely," said Mike Mower, a spokesman for the governor.

"We're optimistic that we'll be able to gain the needed legislative support to move forward," he said.

The income tax proposals would "finish the work we started" in this year's legislative session, said state Sen. Curt Bramble, R-Provo. Lawmakers reduced the sales tax on food, but legislation that would've lowered the income tax rate stalled in the state House of Representatives.

The current proposal would expand the income tax brackets -- currently, all income over $8,400 is taxed at the highest rate of 7 percent. Moving that threshold up would mean more of a person's income would be taxed at a lower rate.

That change would take effect in time for the 2006 tax year. The other component of income tax changes -- a flat tax -- would take effect next year.

If the flat tax option makes it into law, taxpayers would figure their taxes as they always do and then also multiply their taxable income by a flat rate. The lower amount would be the income tax due.

"We're adding one additional computation. It adds two lines to the front page" of the tax form, said Bramble.

"We pushed for true reform for the last three years and we couldn't get legislative support," Bramble added. "This is an incremental step in the reform process. It is a big deal, introducing a flat tax into our system."

The changes would introduce a tax cut estimated at $70 million.

The other measure that would be before lawmakers concerns transit projects in Salt Lake County. Legislation is needed to allow almost $900 million slated for mass transit to come from a sales tax increase instead of a property tax hike.

The money could pay for light rail lines, right of way preservation for the proposed Mountain View Corridor and commuter rail to the Point of the Mountain, Bramble said.

Not everyone is enthused about a special session, however.

"I'm concerned about doing something of a very complex nature in special session," said state Sen. Howard Stephenson, R-Draper and head of the Utah Taxpayers Association. "Special sessions were intended for emergencies. In this case there's no emergency that I'm aware of."

He said income tax reform is needed, but "this leaves too much room for mischief and mistakes."

Besides Bramble, Stephenson said, "I haven't talked to any others who have said, 'Yeah, this is a good idea.' "

They do exist, however. Writing on the House Majority's blog -- www.theutahhouse.com -- state Rep. Wayne Harper, R-West Jordan, said the proposal "provides tax reform, predictability, reliability, stability, flexibility and the opportunity for Utahns to choose what tax method they wish to use to calculate their tax."

There will be a meeting of the Revenue and Taxation Committee Sept. 5, followed by a meeting of the entire Legislature to hear specifics about the proposals. Then members of the House and Senate will break into party caucuses to gauge member support.

"That's why we're having the meetings, so we can assess how they feel," said House Majority Leader Jeff Alexander, R-Provo. "The problem we're having right now is there's no bill, so we don't know exactly what it would do."

House and Senate members started the general session earlier this year with markedly different tax cut goals, but eventually came to the agreement that wasn't fully implemented by the end of the session. This proposal would put that agreement in place, Alexander said.

"I think, for the most part, that's still the agreement," he said.

This story appeared in The Daily Herald on page A1.