Congress returned from recess on Tuesday one day closer to a government shutdown that almost nobody wants.

But lawmakers can’t yet figure out how to prevent it from happening.

Republican leaders in both the House and Senate were mulling options on Tuesday for a stop-gap funding bill that would keep the government open through early December, according to Republican aides. But Democrats rejected the idea before it was even released publicly.

“I don’t think we’re going to be happy with a long-term effort to get to December and then throw up our hands,” House Minority Whip Steny Hoyer (D-Md.) told reporters on Tuesday. “We may run [the government] through October 15.”

Democrats are expected to eventually support a short-term continuing resolution, or CR, that would temporarily maintain current spending levels. But they aren’t willing to throw their support behind the stop-gap measure without concessions from Republicans who spent the majority of this year working to pass deep spending cuts through the appropriations process.

Democrats say they’re willing to back a short-term CR, but only so they can begin negotiations on a long-term deal that increases domestic spending.  And they want to be done well before December.

That’s because December is also around the time the federal government is expected to reach the debt limit past which it cannot, theoretically, borrow cash without defaulting on its obligations. Republican leaders have had a tough time rallying members to increase the federal borrowing limit in recent years, a hurdle that could be made even more difficult if the debt and government spending debates are mixed.

In September, leaders have fewer than ten working days to pass a spending bill before the fiscal year ends on Sept. 30.

Democratic demands create a difficult situation for House Speaker John Bohener (R-Ohio), who is battling an insurgent conservative group within his own party threatening to block any spending bills that include funding for Planned Parenthood, including the stop-gap funding bill. Courting Democrats risks losing more support within his own party by alienating deficit hawks in addition to the rebellious conservatives.

And the insurgent conservatives, led by Rep. Mick Mulvaney (R-S.C.), raised the stakes Tuesday as more members signed a letter vowing to oppose any spending bill that includes funding for Planned Parenthood, including any short-term CR. Aides for Mulvaney would not confirm the exact number of signatories but several Republicans said it was near 30, almost enough to ensure Boehner will need votes from Democrats to avoid a shutdown.

That has more moderate Republicans worried their party’s stand on Planned Parenthood could turn into a political windfall for Democrats. Rep. Tom Cole, (R-Okla.), a Boehner ally, said he also supports ending funding for Planned Parenthood but attaching defunding to the government spending bill is the wrong way to go about it. He said the White House will veto any bill that ends the funding and Republicans will take the blame if the government shuts down as a result.

“[Those vowing to oppose a CR] are setting themselves and others up,” said Cole, a former National Republican Congressional Committee chairman. “Shutting down the government to me probably does nothing but make it more difficult to elect a Republican president next year.”

That leaves leaders only one way to avoid a shutdown: ask Democrats for help. In that scenario, Cole said Planned Parenthood keeps its funding and Democrats walk away on top.

“Your actions have to be calculated to achieve your objectives,” Cole said. “You are far better off to say, “Let’s win some elections, get more senators and a president who will work with us instead of against us on this issue.’”