Representatives of two groups behind the tax initiatives played to an unfriendly audience Friday when they attempted to persuade state and local government officials the millions of dollars in tax cuts were justified.

Members of the Utah Advisory Council on Intergovernmental Relations that gathered sat in silence as Howard Stephenson, vice president of the Utah Taxpayers Association, tried to ease the tension with a little humor.It didn't work. In fact, the first time the 75 or so government officials laughed was when an audience member implied that the Utah Taxpayers Association was looking out for utilities and other big business rather than homeowners.

After the ice was broken by that comment, audience members began arguing with Stephenson and Greg Beesley, head of the Tax Limitation Coalition, the group that got the initiatives on the ballot.

Most of the debate centered on just how much money would be lost if the tax initiatives are approved by voters in November. The pro-initiative groups said $240 million - much less than the loss calculated by the Utah State Tax Commission.

Both sides agree the initiative that would roll back income and other tax increases passed by the 1987 Legislature would cut about $141 million from state coffers. The initiative that would give parents of children in private schools a tax credit has an estimated price tag of about $3 million.

Stephenson said that if the effect of the initiative limiting property tax rates is figured properly, it would reduce tax collections by $80 million - not the nearly $185 million forecast by the Tax Commission.

The difference results from the state law defining how a property's fair market value is determined. Under the law, fair market value is the price that would be agreed to by both a seller and a buyer, minus 20 percent.

Stephenson claimed that the property tax initiative was drafted and circulated before a change in the legal definition of fair market value was approved by the 1988 Legislature.

Audience members, however, suggested that members of the Utah Taxpayers Association made a mistake when it drafted the initiative by not spelling out that they wanted to place limits on 100 percent of a property's fair market value, not 80 percent as the law requires.

Several also said taxes have been assessed on 80 percent of a property's fair market value since the early 1980s and that the 1988 change in the law just moved a reference to the definition of fair market value from one place in the statutes to another.

Salt Lake County Commissioner Bart Barker gave Stephenson his only chance to get a laugh from the audience when he asked whether he would be willing to ask lawmakers to limit the reductions mandated by the initiative to $80 million.

"Yeah," was Stephenson's response to Barker's lengthy question.

Beesley, though, drew the loudest heckling when he responded to Barker's suggestion that the groups admit they made an error in the initiative and tell the public its true cost.

"Of course we're not going to give any ground that we've got. That's reasonable isn't it?" he asked.

"No, be honest" one woman shouted from the audience.

The groups were invited to appear before the council at its daylong meeting on Friday at the Salt Lake County Government Center to discuss proposed reductions outlined by council members at a meeting earlier this summer.