House Republicans are scheduled to meet at noon Saturday to hash out an agreement over how to proceed on a budget bill that must be signed into law by Monday to avoid a government shutdown.

The House majority's 11th-hour wrangling comes amid intra-party disagreements over how to respond to the government spending bill that cleared the Senate Friday. The Democratic chamber stripped from that House-approved bill a Republican provision that would have defunded Obamacare.

House Speaker John Boehner, R-Ohio, has made clear Republicans would not accept this “clean” Senate version, but his caucus has yet to determine what changes could muster the 217 GOP votes they'd need to pass. Sources familiar with the Republican leadership’s planning for Saturday’s meeting expect the leaders to present rank-and-file Republicans with a single proposal and urge them to approve it and send it to the Senate the same day. GOP sources stressed that the situation was extremely fluid.

“We’re reviewing our options, and will discuss them with members tomorrow,” Boehner spokesman Michael Steel said late Friday.

House conservatives who are insisting that the House use the spending bill to defund implementation of the Affordable Care Act, even at the risk of a government shutdown, signaled Friday that they could support a new proposal to delay, rather than defund, Obamacare. Republican sources said that a proposal to attach a provision delaying Obamacare's implementation to the bill could be the option presented to members Saturday, although other ideas could also be discussed and considered.

The House is likely to vote Saturday regardless of whether Republicans have secured the support of enough of their members to call a vote on the budget bill, which must pass to avoid a government shutdown on Tuesday. The majority caucus numbers 233 and can only afford to lose 16 members and still pass the bill without Democratic participation on which they can not count.

The House Republicans least worried about the political consequences of a government shutdown favor sending the Senate a budget bill that includes a provision that delay Obamacare.

“We still think you should delay Obamacare,” Rep. Jim Jordan, R-Ohio, and influential House conservative, said. “Let’s delay it — and not defund it forever, delay it for one year. … We think that makes sense, a simple delay; this is reasonable.”