House GOP leaders are struggling to settle on a plan to open the federal government and raise the country's debt ceiling that would placate the most conservative members of their rank and file, while Senate leaders grow increasingly concerned that the House's latest actions could stymie a bipartisan agreement they are close to brokering to end the standoff.
Republicans in the House aim to build off the work of Senate leaders, but adding new sweeteners to their own plan that could help more conservative members get on board with a compromise.
The House plan would likely include more changes to President Obama's health care law, including a delay in a tax on medical devices and a provision that would force members of Congress, their staff and cabinet members to get their health insurance from exchanges without government subsidies.
But even before the details of the plan emerged, the White House signaled that President Obama would reject it, which he has.
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House Republicans, amid the challenge of pushing Democrats for more concessions in a compromise deal, began their 9 meeting today by singing the hymn "Amazing Grace" to "strengthen their resolve," according to a senior GOP aide.
After that meeting with rank and file, which lasted nearly two hours, House Speaker John Boehner said there have been "no decisions" about how the House would move forward.
"There are a lot of opinions about what direction to go," Boehner told reporters this morning. "But we are going to continue to work with our members on both sides of the aisle to try to make sure there is no issue of default and we get our government reopened."
Meanwhile, Senate Majority Leader Harry Reid, D-Nev., and Senate Minority Leader Mitch McConnell, R-Ky., who have worked through the weekend and into this week hammering out the details of a potential compromise, met at the start of the day this morning behind closed doors.
After the meeting, Reid said on the Senate floor that the talks have been "productive" and he is "confident" a deal will be struck this week.
But after details of the House plan emerged, Reid angrily denounced it on the Senate floor.
"It's a plan to advance an extreme piece of legislation, and it's nothing more than a blatant attack on bipartisanship," Reid said. "In the past several days, we've been engaged in productive bipartisan negotiations in the Senate. Everyone knows that."
"Everyone needs to know that the measures under discussion in the House is no part of what we've negotiated here in the Senate," he added.
Talks between Reid and McConnell are now on hold because of the House GOP proposal, Sen. Bob Corker, R-Tenn., said. Several Republican senators now say they will wait to see exactly what the House produces.
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The dueling House-Senate plans are in agreement on two important terms: the length of a debt-limit increase and government funding. The differences revolve largely around which provisions of the president's health care law will be changed.
In a statement, the White House rejected the House plan as a "ransom" demand.
"The President has said repeatedly that Members of Congress don't get to demand ransom for fulfilling their basic responsibilities to pass a budget and pay the nation's bills," White House spokesman Amy Brundage said this morning.
"Unfortunately, the latest proposal from House Republicans does just that in a partisan attempt to appease a small group of Tea Party Republicans who forced the government shutdown in the first place."
Brundage also signaled that the White House remains supportive of the direction that negotiations between Republicans and Democrats are going.
The two chambers would need to reconcile any differences before the Oct. 17 deadline in order to avoid reaching the debt ceiling.
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The White House indefinitely put off a meeting with congressional leaders at the White House Monday afternoon to give lawmakers more time to hammer out the details of a compromise.
The move was viewed as a positive sign that an end to the government shutdown that has so far lasted 15 days is near. And a deal would also raise the debt limit by the Thursday deadline.
Obama now plans to meet with House Democratic Leadership at the White House today at 3:15 p.m.
The broad contours of the Senate compromise include funding the government until Jan. 15 and raising the debt limit through February 7.
Though those terms would take these debates largely off the table though the holiday season, it would only kick the can down the road. Eventually, lawmakers will face a similar need to both extend funding for the government and raise the debt ceiling in 2014.
The deal could also include some provisions that address the president's health care law, but the negotiations notably exclude any of the demands Republicans initially made to either defund or delay the law's central provisions.
The Senate is still considering including income verification for people eligible for health care subsidies, a provision that House Republicans also want included in a deal. But the Senate Democratic leadership and the White House are opposed to changes or delays to the medical device tax, a proposal Republicans have included in their plan.
But both the House and Senate proposals represent an about-face for Republicans who have been saddled in public polling with an overwhelming majority of the blame for the shutdown. And it is unlikely to please Tea Party conservatives who still insist that significant alterations to the Affordable Care Act must be part of any budget deal.
House Minority Leader Nancy Pelosi, D-Calif., slammed the House GOP plan, suggesting that not even that plan has enough votes among Republicans for it to pass in the House.
This Republican strategy of sabotaging any effort to move forward is a luxury our country cannot afford," Pelosi said today.
On Monday, Sen. Ted Cruz, R-Texas, who led the Tea Party charge in the Senate, said he would reserve judgment until he knew the full details of a potential agreement.
"I want to wait to see what the details are," Cruz said.
And a potential deal could face an uphill battle in the House of Representatives.
Monday night as Senate leadership left the Capitol optimistic about progress that had been made in negotiations, Cruz met with nearly two dozen House Republicans at a popular Capitol Hill hangout, Tortilla Coast, to strategize how they would respond to the emerging deals.
Cruz's office confirmed to ABC News that he attended the meeting but would not say what was discussed.
An ABC News/Washington Post poll Monday found that dissatisfaction with the party is accelerating. Seventy-four percent of Americans disapprove of the Republicans' handling of the budget crisis, compared with 63 percent two weeks ago and 70 percent last week.
The numbers in other polls have also been frighteningly bleak for Republicans. A Thursday NBC/Wall Street Journal poll gave the Republican Party the worst approval numbers in the poll's history. And it found that support for Obama's health care law has improved since Oct. 1, when people could go online to sign up for insurance coverage.
ABC News' Jeff Zeleny contributed to this report.