Rep. Jeb Hensarling (R-Texas), co-chairman of the Joint Committee on Deficit Reduction, said today the panel is not giving up its quest to reach a deal — and that Republicans have not made their last offer.

In a rare media availability, Hensarling said he believed both parties are still acting in good faith and that Republicans had made a “major concession” in their most recent offer to Democrats by including provisions that could levy up to $300 billion in revenues by reforming the tax code to eliminate deductions. The brief exchange with the press came the day after tensions on the panel hit another high over the proper balance of tax hikes and changes to entitlement programs.

“The short answer to your question is ‘no,’” Hensarling said when asked if this week’s GOP offer was the last. “I’m not giving up hope, and I hope my Democratic colleagues aren’t giving up hope until midnight on [Nov.] 23. Now we’ve got a very practical challenge in getting something to the Congressional Budget Office. I acknowledge that. But the stakes are too high for our economy to throw up our hands and give up. And so we’re not.”

The “practical challenge” of getting a score from the nonpartisan budget scorekeepers is not the biggest obstacle to a deal. Both parties have been submitting large swaths of policies to the CBO to have scores on hand in the event they reach an agreement. The real hurdle is whether Democrats and Republicans can come to the middle on the balance of spending cuts, taxes and changing entitlement programs.

Hensarling said Republicans have given enough on taxes in their most recent proposal, a $1.2 trillion plan comprising $500 billion in revenue and $700 billion in cuts.

“We have an offer on the table where we have made considerable concessions,” Hensarling said. “We believe that pro-growth tax reform is part of the jobs crisis solution and the debt crisis solution, which is why we put it on the table in the first place. So we remain hopeful. This is not part of a blame game.”

But it’s unclear that the proposed GOP tax code changes, made by eliminating deductions for high-income taxpayers, could achieve the stated goals of the plan. The framework, first introduced to a group of seven panel members Monday evening by Sen. Pat Toomey (R-Pa.), would use the tax code savings to put $250 billion to $300 billion back toward the deficit and lower the marginal tax rate for the highest earners to 28 percent.

Hensarling indicated such a policy move is similar to previous bipartisan efforts, and while recent initiatives did seek to lower rates and eliminate tax loopholes, they also addressed major tax areas such as capital gains, dividends and mortgage interest.

“It is exactly the same process that has been used by every other bipartisan effort, be it Rivlin-Domenici, Simpson-Bowles, be it the ‘gang of six,’ and that is you start to clear out the tax expenditures — the tax loopholes — and you do that in order to bring down rates and generate more revenue,” Hensarling said. “We can debate the revenue level, but the approach is exactly the same.”

The Bowles-Simpson report generated by the president’s deficit reduction commission, for example, proposed to tax all capital gains and dividends at ordinary income rates, as opposed to 2011’s top rate of 20 percent, and placed caps on the deductibility of mortgage rates.

Though discussion of revenues is certainly a step forward for the panel — even top lawmakers outside the group acknowledged that this week — there is a considerable way to go before a deal and less than two weeks to do it.