(J. Scott Applewhite/AP)

Rep. Jeb Hensarling (R-Texas) and Sen. Patty Murray (D-Wash.), co-chairs of the debt supercommittee.

This post has been updated.

With the bipartisan debt supercommittee set to throw in the towel as early as Monday, the panel’s co-chairman Sunday called the group’s anticipated failure a “huge blown opportunity.”

“I don’t know what the impact on the market will be,” Rep. Jeb Hensarling (R-Texas) said on “Fox News Sunday” of the 12-member panel’s likely stalemate. “I would hope there wouldn’t be an adverse impact in the sense that the American people are still going to get the deficit reduction that was contemplated under the law. But it is a huge blown opportunity, and as a nation, we are on borrowed time.”

Hensarling was one of seven members of the joint committee who made the Sunday show rounds ahead of the panel’s deadline of midnight Monday. If, as expected, the 12-member group fails to reach an agreement by then on a plan to reduce the deficit by at least $1.2 trillion over the next decade, then a $1.2 trillion across-the-board cut to defense and non-defense programs will go into effect beginning in January 2013 – an outcome that some lawmakers have increasingly said they will work to undo.

Members of the panel are expected to announce as soon as Monday that they have been unable to reach an agreement as they remain deadlocked over the parties’ perennial differences on taxes and entitlement reform.

Asked by Fox News channel’s Chris Wallace how he expects the end of the panel’s work to play out, Hensarling, the supercommittee’s House co-chairman, responded simply, “I don’t know.”

“People have invested so much in this,” Hensarling said. “Nobody wants to give up hope, so I can’t answer that question. And so until we have the stroke of midnight I suppose on Monday, as long as we have members who have an opportunity to continue to talk we’ll continue to talk.”

But in a tacit acknowledgment that the panel has been unable to reach an agreement, Hensarling spoke of the supercommittee’s work in the past tense when asked about the potential impact on the financial markets.

“It wasn’t so much of a failure as it was a failure to seize an opportunity, and it’s not this opportunity, this nation better seize another one or we will be in big economic trouble,” he said.

Sen. Patty Murray (D-Wash.), the Senate co-chair of the debt panel, argued Sunday morning that it’s up to Republicans to come forward with a plan that would include tax increases on the wealthy.

“I’m going to be waiting all day,” Murray told host Candy Crowley on CNN’s “State of the Union.” “I’ll be at the table, as I’ve been, willing to talk to any Republican who says, look, my country is more important, this pile of bills is not going to go away, the challenges that we have is not going to disappear, we need to cross that divide. I’m ready. I’m waiting. Today I’ll be at the table, all night long. We have a few hours left.”

Murray said that she still believes “strongly” that Congress will be able to come together to address the country’s debt problem, even if the supercommittee isn’t able to do so.

“I believe strongly that we still have the capability to come together to solve this problem,” she said. “If the supercommittee can’t do it, then I hope that Congress will. In fact, I’m committed to solving this. You can’t just ignore this crisis.”

Rep. Xavier Becerra (D-Calif.), another member of the bipartisan committee, appeared on “Fox News Sunday” after Hensarling and said he still believes the panel will be able to reach a deal.

“I don’t think we’re going to give up on an opportunity to get this done, because it’s better than letting automatic triggers decide where we’re going to make the cuts. ... I don’t think there’s failure yet,” he said.

With failure imminent, members on both sides of the aisle sought to blame the other for the lack of a deal. Hensarling argued that “it’s not about assigning blame, but we are unaware of any Democratic offer that didn’t include at least a $1 trillion tax increase on the American economy.”

Becerra countered that Republicans were the ones who were unwilling to make concessions on taxes and that Democrats had put forth plans that would have made changes to entitlement programs such as Medicare and Medicaid.

“Every plan that Democrats have put forward has included cuts to entitlement programs,” Becerra said.

The imminent failure of the supercommittee leaves Congress with a host of unfinished business, such as whether to extend unemployment benefits and the one-year payroll tax cut. Those items would likely have been included as part of any broader deal put forth by the panel and fast-tracked through Congress. But now, Congress must figure out a way to deal with each of those issues one-by-one, and in a political environment that is particularly charged less than one year out from the 2012 election.

“I don’t know the answer to that,” Hensarling said when asked about the extension of unemployment benefits and the payroll tax holiday. “Certainly, we would want to make sure that they are paid for. We know that the two – both the debt crisis and the unemployment crisis – are related, and so that’s something that Congress would have to debate.”

There’s also the matter of the across-the-board spending cut that is set to take place in 2013 if the panel fails. Hensarling, who has earlier suggested that he would support efforts to re-work the cut so as to spare Pentagon spending, said Sunday that he plans to take part in an effort by lawmakers to do so.

“I hope it will be changed. ... I want people to know that I am going to be committed to ensuring that the American people get the deficit reduction they were promised. But under the law, Congress will have 13 months to do that in a smarter, more prudent fashion and I plan to be a part of that process,” he said.

Becerra called it “a wimpy way out” to try to re-work the across-the-board cut, noting that the composition of the cut was already agreed to by members of both parties in the August debt-ceiling deal.

“You have to have some discipline,” he said.

On NBC’s “Meet the Press” Sunday morning, supercommittee members Sens. Jon Kyl (R-Ariz.) and John F. Kerry (D-Mass.) refused to say flat out that the committee had failed. But both spoke of its potential in the past tense, and blamed the other party for spoiling it.

“Our Democratic friends were never able to do the entitlement reforms,” Kyl said, arguing that Democrats were the roadblock to a deal. “They weren’t going to do anything without raising taxes.”

Kyl said that Republicans had been the one party willing to alter a cherished policy position, with a plan from Sen. Pat Toomey (R-Penn.) that offered $300 billion in new taxes.

“Nothing new came out of this from the Democratic side,” Kyl said. “On the republican side, we had the one true breakthrough.”

Kyl, a strong backer of defense spending, was asked by host David Gregory about the automatic cuts to the Pentagon budget—now mandated by law if the supercommittee fails.  Kyl indicated that those particular cuts might be undone, or shifted into other areas of the federal budget, so that the automatic cuts would still total the promised $1.2 trillion.

“I can’t imagine that--knowing the importance of national defense--that Democrats and Republicans wouldn’t find a way to work through” an alternative to the Pentagon cuts, Kyl said. “When the reality sets in, even those Democratic friends who would like to see more defense cuts…will find a way to work around this.”

Kyl said that he did not want to see the total amount of the “sequester” changed, even if the defense cuts were watered down.

“There’s going to be 1.2 trillion dollars in savings,” Kyl said, when asked about the potential for further downgrades of the U.S. credit rating. “So this shouldn’t foster a downgrade.”

A few minutes later, Kerry said that Republicans had blocked the committee’s work by demanding an extension of Bush-era tax cuts and refusing to consider significant tax increases on wealthier people.

Kerry insisted that Democrats were willing to sacrifice their priorities, by offering cuts in programs like Medicare. Following a familiar Democratic line of attack, he blasted Republicans for refusing that kind of deal, blaming their loyalty to a no-tax-increases pledge made to anti-tax activist Grover Norquist.

“We’re here all day. We are ready to do 1.2 trillion,” in overall cuts to the deficit, Kerry said. “We’re ready to do it, if they will give up their insistence on the Bush tax cuts.”

Gregory asked Kerry about President Obama’s role in the supercommittee’s work—in which the president has played a much less visible role than he did in the summer’s debt-ceiling fight.

“They were asked to be hands off ,” Kerry said, meaning the White House. “The Republicans said, ‘Don’t let Obama come into this, because if he does, it will make it political.’”