But an unrelated proposal to allow counties to switch from property tax to sales tax to pay for public transit, which the governor and Salt Lake business leaders had hoped to piggyback on the tax session, likely is dead after Republican senators failed to endorse it in their caucus.

"That is something we will have to evaluate as to whether it will be on the special session call because we received mixed signals on it from the Senate and House caucuses," said Huntsman's spokesman Mike Mower. The governor, however, pleased by the overwhelming support for the tax change, will likely call a special session on either Sept. 19 or Sept. 20, Mower said.

Huntsman, who says an income tax overhaul is central to his economic development plan, told lawmakers the so-called dual-tax proposal is only a first step toward more comprehensive tax reform.

And the special session will finally allow lawmakers, most of whom face reelection in November, to give voters a $70 million tax cut they promised - but failed to deliver - in March.

At a Revenue and Taxation Interim Committee meeting and in later caucuses the dual-tax plan was picked apart Tuesday by lawmakers, lobbyists and low-income advocates. Democrats and community activists generally oppose it, saying it does little to protect and increase education spending, which is entirely funded by the income tax. They also fear it could undermine charitable giving.

Under the plan, tax brackets in the existing structure would be slightly expanded for 2006. The most dramatic change is that beginning in 2007, taxpayers also would be offered an option of a flat rate of 5.4 percent, without deductions or credits.

The current system has a top rate of 7 percent, which Huntsman says hamstrings Utah in competing with surrounding states for new or expanding businesses.

But tax experts say that, with deductions and credits rolled in, Utah's effective rate is really closer to 5.5 percent.

Supporter Sen. Curt Bramble, a tax accountant and a leader of the Revenue and Taxation Committee, said the dual-tax system is "really one system with a choice of rates." The new structure adds little complexity to Utah's income tax filing, he says, just two lines at the end of the tax form.

A proposal to amend the bill to index the new brackets for inflation failed, even though many Democratic and Republican lawmakers supported such built-in inflation protection. "We don't want to have to come back in five years and try to make up for what is lost without indexing," said Sen. Howard Stephenson, R-Draper.

Senate President John Valentine predicted the indexing issue would be taken up in the next regular session in January. "It's important to add indexing to the brackets."

The Senate Republican Caucus did not support the transit sales tax proposal, Valentine said, because lawmakers would not have time to get serious questions answered. Without enough votes to pass in the Senate, he said there was little point in bringing the issue up in the planned one-day session.

Still, some lawmakers complain the dual-tax proposal falls far short of comprehensive tax reform, something the Legislature has been debating for more than two years, and fear the partial measure will sap momentum for a more thorough overhaul.

"This is a step toward reducing volatility and broadening the base," countered Valentine. "It's not an end in itself. It positions us for downturns of the economy because it makes the system less volatile."

Bramble was more blunt: "This is as far as we could move the reform agenda, taking into account the political environment."

House Majority Leader Jeff Alexander said Republican representatives were less optimistic about future tax reform. "This will be a dual tax system for a long time," he predicted.

More important than so-called reform schemes, Alexander said, is that taxpayers will pay less in taxes under the plan as government growth is stunted.

"They want their money back," the Provo Republican said of his constituents. "That is what I hear more than anything else in my district."

Polls, however, have found that Utahns would prefer the tax cut be plowed into education and roads.

Advocates for the poor say the plan favors the wealthy while doing much less for the middle class and poor. Only 4 percent to 5 percent of taxpayers at the top of the scale who have few deductions would benefit from the flat rate.

Democrats found little reason to recommend the plan, other than any expansion of tax brackets - particularly with inflation indexing - is better than the existing system. In their House caucus, they supported putting the tax cut, which amounts to $4 per month for most families, into education. Utah is last in the nation for per-pupil spending.

"If I knew the increased revenue from the $70 million tax cut was going to [bolster] education, it would be one thing," said Rep. Brad King, D-Price. "But there's no guarantee that will happen."

Huntsman argues that reducing the state's top income tax rate from 7 percent to 5.4 percent will lure top executives and their companies to Utah rather than surrounding Western states.

But Sarah Wilhelm, an economist for Voices for Utah Children, told lawmakers that little correlation exists between tax cuts and economic development.

"This will cause a small uptick in our economy," she said. "It certainly won't have enough impact to pay for the $70 million tax cut."

What it means

The $70 million tax cut is estimated to mean an average $48 break for families ($24 for single filers).

Roughly equal to the price of one gas fill-up for the family minivan,

or a medium-stem white rose bouquet with vase from FTD,

or Season 4 of the TV drama ''24'' on DVD,

or a personal body fat monitor,

or a Leatherman pocket tool.

Of the reduction:

$40 million would go toward spreading tax brackets in the current system.

$30 million

would pay for implementing an optional flat tax.