Even as they hammer Democrats for running up record budget deficits, Senate Republicans are rolling out a plan to permanently extend an array of expiring tax breaks that would deprive the Treasury of more than $4 trillion over the next decade, nearly doubling projected deficits over that period unless dramatic spending cuts are made.

The measure, introduced by Senate Minority Leader Mitch McConnell (R-Ky.) this week, would permanently extend the George W. Bush-era income tax cuts that benefit virtually every U.S. taxpayer, rein in the alternative minimum tax and limit the estate tax to estates worth more than $5 million for individuals or $10 million for couples.

Aides to McConnell said they have yet to receive a cost estimate for the measure. But the nonpartisan Congressional Budget Office recently forecast that a similar, slightly more expensive package that includes a full repeal of the estate tax would force the nation to borrow an additional $3.9 trillion over the next decade and increase interest payments on the national debt by $950 billion. That's more than four times the projected deficit impact of President Obama's health-care overhaul and stimulus package combined.

"We have a spending problem. We spend too much. We don't have a taxing problem. We don't tax too little," McConnell told reporters Tuesday. "And if we want to begin to get ourselves out of this economic trough that we're in, the only way to do that is to grow the private sector."

McConnell spoke as senators returned to the Capitol after a six-week hiatus for a final pre-election session that will be defined by a battle over the Bush tax cuts. Unless Congress acts, the cuts will expire at the end of the year, raising taxes across the board.

While Republicans want to preserve all the cuts, Obama has called on lawmakers to extend them only for household incomes under $250,000 a year. That strategy, he argues, would knock hundreds of billions of dollars off the cost of extending the cuts, money that could be used to reduce the nation's debt.

Senate Democrats, while generally supportive of Obama's position, have yet to determine the precise shape of the package they hope to put to a vote in the next four weeks.

(READ RELATED ARTICLE: Putting the $3.9 trillion extension of the Bush tax cuts in context)

The issue dominated a luncheon meeting Tuesday, but Senate Democrats reached no consensus on how to proceed. Some lawmakers want to hold a vote on the Obama plan - which would presumably not achieve the 60 votes needed to overcome a GOP filibuster - and then adjourn until after the election. Others prefer to try to resolve the issue before the current session ends to provide voters with certainty on the matter. But that would require at least a handful of Republicans to agree to a compromise, probably involving a temporary extension of all the tax cuts.

Sen. Olympia J. Snowe (R-Maine) signaled her openness to such a deal Tuesday. "Where we start is to extend all the tax cuts. I think that's important," she told reporters. But she also suggested that she might accept a solution that falls short of a permanent extension of all the Bush cuts - the only approach her more conservative Republican colleagues say they are willing to consider.

A handful of Democrats say they, too, would like to see all the tax cuts extended, at least temporarily, to avoid raising taxes amid an economic downturn - and to blunt GOP charges, in the final weeks before critical elections, that Democrats are raising taxes.

Senate Majority Whip Richard J. Durbin (D-Ill.) said it's an open question whether any tax vote will occur in the Senate before the election. "It's more likely than not, but no final decision" has been made, he said.