The amount of cash Florida lawmakers will have on hand to build next year’s state budget looks likely to drop from earlier predictions by between $1.4 billion and $1.7 billion, according to estimates unveiled Tuesday by state economists.

The state’s Revenue Estimating Conference, a gathering of analysts representing the Legislature, state Department of Revenue and Gov. Rick Scott’s office, are meeting most of the day to update their latest forecast of tax collections.

 The amounts settled on Tuesday will guide the budget proposal Scott will present later this year to the Legislature — and go a long way toward shaping the spending plan lawmakers put together when they begin the 2012 session in January.

The House budget committee last week said that because of declining tax receipts and rising costs — particularly in public schools and Medicaid spending – that a shortfall of $1.1 billion to $2.2 billion was expected, likely resulting in another round of program cuts and employee layoffs next year.

Tuesday’s revenue forecast looks likely to bolster those storm cloud predictions. Sales tax collections — which provides about three-quarters of the state’s general revenue — is the root of the state’s problem.

In a faltering economy,  sales tax receipts are expected to be down as much as $881.4 million next year from the estimating conference’s forecast earlier this year. Sales tax dollars also are off earlier estimates by as much as $257.5 million in the current budget.

Rising government costs and crumbling tax collections are leaving lawmakers facing a $2 billion budget shortfall next year, Senate President Mike Haridopolos said Thursday, a prospect few saw coming only months ago.

“Everything is on the table,” said Haridopolos, R-Melbourne, although he acknowled that tax increases are not. “But in June, I thought we’d be in a continuation budget. All the signs had us pointing in the right direction….But now we’re very concerned with revenue shortfalls.”

The House budget committee earlier Thursday estimated that lawmakers could come up between $1.1 billion and $2.2 billion short next year. The current year’s $69 billion budget was balanced by cutting spending, pulling cash from trust funds, and making government employees pay 3 percent of their pay to help cover pension costs.

A similar balancing act looks likely to commence in January, when lawmakers convene the 2012 session.

Florida economists are scheduled to meet Tuesday. They are expected to revise the state’s revenue forecast downward, with tax collections declining in the increasingly fragile economy.

Glimmers of trouble were evident this week, when funding for courts, road projects and school construction all reported shortfalls linked to the economy. But the news is a sharp departure from early last month, when economists forecast three years of clear budget sailing.

At that time, though, another leading senator, Don Gaetz, R-Niceville, conceded lawmakers would be wise not to celebrate over what appeared to be sufficient revenues to cover state spending through 2015.

Gaetz, in line to lead the Senate following next year’s elections, said last month that Florida’s economy is “on a knife’s edge.”

“We can’t move much, one way or the other, without some real damage,” Gaetz said.

House Budget Chair Denise Grimsley, R-Sebring, said next year was beginning to look all to familiar.

 “2012 is going to be another challenging year as we face a potential $2 billion shortfall; however, I am confident we will once again solve our budget challenges while keeping taxes low and encouraging private sector economic activity,” Grimsley said. 

State economists are hashing out their new estimate of how much less money lawmakers have to spend this year.

Their last general revenue estimate projected the state would collect about $3.6 billion less this year in taxes and fees than last. But this morning’s estimates range from an additional $332.4 million drop – bringing the deficit to $3.9 billion – to a gain of $47.4 million that would decrease the spending gap to closer to $3.5 billion.

The three groups of economists representing the legislature’s Bureau of Economic and Demographic Research, Gov. Rick Scott and the Department of Revenue will crunch numbers throughout the day.

EDR’s initial $332.4 million in additional lost income is the highest. Scott’s office projects an extra $109.7 million drop. And the department’s was the rosiest – a gain of $47.4 million.

The average of the three – $131.6 million – would bump up the deficit to $3.75 billion.

First, the good news: Florida’s fiscal forecast hasn’t changed much since the last time state economists met in December.

Now, the bad news: The state’s still facing about a $2.2 billion budget shortfall in its general revenue collections.

In December, the economists estimated about $22.5 billion in sales and other tax collections for 2010-2011.

Now, the legislature’s Bureau of Economic and Demographic Research is predicting that tax collections and other fees will bring in about $2.2 million less than the December projection, close to the Department of Revenue’s estimates that the collections will come in about $65.9 million short.

But Gov. Charlie Crist’s office is revising its estimate in the other direction, a reflection of the governor’s perennial optimism.

Crist’s budget gurus think the state will bring in $257.3 million more than they previously anticipated.

The revenue estimating conference will meet throughout the day and provide their final prognostications this afternoon.

But Gov. Charlie Crist’s office is showing about the about meeting with Gov. Charlie Crist’s budget gurus and the Department of Revenue’s economists