Sen. Johnny Isakson (R-Ga.) told CNN Monday morning that he believed lawmakers had reached a deal on revenue but not on spending. 

“First of all, I’m not sure we have the inside information, but I do believe the revenue issue is no longer a question," he said. "The question is making sure any new revenues go toward debt spending reduction and deficit relief rather than new spending.” 

Asked if he was certain there was a deal on revenues, Isakson replied, “No, that's not my best information, but it's my best belief that they've reached an agreement on revenues. What that level is, I don't know, but the question now is where those revenues go. If they go to new spending, we're going to have a problem making a deal because spending has been our problem. But if they go toward deficit reduction, which ultimately will be debt relief, that will be a good thing, and we probably will have a deal.”

Talks are continuing as Democrats have offered several significant concessions on taxes, including a proposal to raise rates only on earnings over $450,000 a year.