Another potential government shutdown could loom if Congress isn’t able to scramble soon and cobble together a big omnibus spending bill to keep the government open past Dec. 16.

The current stopgap measure expires then. And only three of the 12 annual spending bills which run the federal government have been approved and signed into law.

That means House and Senate appropriators are putting together a massive, omnibus spending bill which they hope to have prepared by Dec. 15. This would not be an interim bill, better known in Capitol Hill-ese as a Continuing Resolution, or CR, which funds government in increments while the regular appropriations bills are negotiated.

This would simply allocate money for the remainder of currently unfunded government programs through Sept. 30, 2012. I am told that House appropriators are resistent to attaching any extraneous issues to this omnibus bill … such as unemployment insurance (UI), a payroll tax holiday, the alternative minimum tax (AMT) or the “doc fix” for Medicare.

What is significant here is that House Speaker John Boehner and GOP appropriators are turning their attention away from conservative Republicans who want to cut spending more and are insisting on a host of social riders in the spending bills, such as defunding health care reform, slashing funding for the Environmental Protection Agency and National Labor Relations Board, eliminating aid for Pakistan and abortion.

Boehner, R-Ohio, knows that he can’t sate his conservative base in the House any more when it comes to these issues. So he may be willing to punt and team with Democrats to keep the government open.

That has the potential to inflame conservatives who are upset that the GOP hasn't made deeper cuts this year. But the GOP leadership points out it has "changed the conversation" in Washington where people are now talking about reducing spending rather than increasing spending.

An example of this already played out on Nov. 17 on the “minibus” spending bill to fund three sectors of the government and keep the rest of the government open until Dec. 16.

That vote was 298-121. But Boehner got 165 Democratic votes for that measure compared to 133 Republicans. Republicans will scream bloody murder now, but the vote on the minibus, with Democratic support, weakened the position of the GOP leadership to do it any other way.

“Our conference is fractured,” said a senior Republican aide familiar with the appropriations process. “We must craft a bill that’s going to pass.”

House Majority Whip Kevin McCarthy (R-CA) is in charge of finding the votes to pass bills. McCarthy spokeswoman, Erica Elliot says her boss can't begin counting votes now without an omnibus bill on the table. But she believes the GOP leadership will successfully court Republican votes when the time comes.

"We know our appropriators are working day and night to negotiate legislation that Republicans can support," Elliott said. "So we're confident we'll have a strong vote when this legislation is brought to the floor.

The “Big Four” appropriators from the House and Senate could meet on Thursday, and it’s possible Boehner could caucus with Senate Majority Leader Harry Reid, D-Nev., could meet soon.