A bipartisan group of senators is working on a proposal to end the government shutdown and ease the debt ceiling standoff.

Sources caution that the situation remains highly fluid and that multiple proposals are in play. But a group led by Sens. Susan Collins, R-Maine, and Joe Manchin, D-W.Va., are developing a possible framework that could include raising the federal borrowing limit for six weeks and approving a government funding bill that would run anywhere from six months to a year.

This blueprint also could include repeal of Obamacare’s medical device tax and a requirement that anyone applying for a government subsidy provide proof of their income. The proposal would redefine the work week from the 30 hours set by Obamacare back to 40 hours, which could prevent employers looking to get around the law from restricting employee work time to 29 hours per week.

Also on the table under this plan is flexibility to restore at least some of the across-the-board spending cuts imposed by sequestration and consideration of delaying some of the Obamacare taxes.

The negotiators pushing this proposal include Collins, Manchin, Sen. Chuck Schumer, D-N.Y., and Republican Sens. Johnny Isakson of Georgia and John McCain of Arizona. Isakson and McCain, who joined all Senate Republicans at a White House meeting with President Obama on Friday, suggested that their bipartisan framework could pass both chambers. However, they declined to provide any plan details or say how Obama reacted to it.

“There are a lot of good talks going on and things are progressing,” Isakson told reporters. "But I don’t want to get into any specifics.”

McCain called the new framework workable, but cautioned: “I don’t know if the White House would agree with me.”

Senate Republicans in particular would prefer a budget bill that kept the government open for a year, as long as it adhered to spending caps that match the sequestration cuts.

Many House Republicans have been more interested in dismantling Obamacare and securing entitlement reforms as a part of the next debt ceiling deal. But most Senate Republicans are committed to protecting the sequester spending cuts they secured in 2011. That factor could influence the outcome of this debate in the coming days.

Meanwhile, congressional Republicans now generally believe that they are in the midst of negotiations with Obama over reopening the government and raising the federal borrowing limit ahead of Thursday’s deadline. Obama has said he will not negotiate those items. McCain said he would characterize the conversations with Obama as “discussions.” But Isakson said as far as he’s concerned, the two sides are “negotiating.”

“That argument’s over, in my personal opinion,” Isakson said. “Communication lines are open and nobody’s hanging up on anybody.”