As the House prepares to vote on the GOP's Middle Class Tax Relief and Job Creation Act today, the prospect for another government shutdown is quickly brewing as Congress works to conclude its mandatory business before heading home for the holidays.

House Speaker John Boehner says that appropriators from both parties in both chambers have agreed to terms on a so-called "megabus" - seven outstanding appropriations bills bundled together to fund government through the end of the fiscal year. But Senate Majority Leader Harry Reid is preventing the conference report from moving forward until a deal is struck on the payroll tax cut extension and unemployment insurance.

"They've smiled at each other, they've shook hands, and it's done," Boehner, R-Ohio, said. "I'm hopeful that the Senate leaders will come to their senses, allow members to sign this report, and move forward. There is no reason to hold this bill up."

Leaders from both parties concede the megabus is nearly finished, but the spending bill might be the only leverage left for Reid as he pushes for clean extensions to the payroll tax credit and unemployment insurance.

House Republican Conference Chairman Jeb Hensarling said that "the American people want jobs" and Reid should get out of the way and into the Christmas spirit.

"Somebody needs to tell Senator Reid it is Christmas, not Halloween. He ought to quit scaring the American people and he ought to let this appropriations bill pass," Hensarling, R-Texas, said. "If Senator Reid wants to hold up the jobs bill, then he will go on Santa's naughty list."

This afternoon the House is expected to pass the GOP's legislation, which the president has threatened to veto. The package extends the payroll tax credit, reforms and extends unemployment insurance, and includes the sustainable growth rate Doc-Fix. Even though the three items are top priorities for President Obama, most Democrats are expected to reject the bill because it includes a provision accelerating the president's decision whether to move ahead on the Keystone XL Pipeline within 60 days of passage.

The Democratic leadership is whipping its members to oppose the bill, but with some moderate Democrats indicating they'll support the bill, Boehner predicted that it "will pass with bipartisan support."

"We've got a reasonable, responsible bill that really will help the American people, really will help create jobs," Boehner said. "The president says that the American people can't wait for jobs. Well clearly if we pass this bill today we will be taking the first big step toward creating jobs in America and it will be time for the United States Senate to act."

Minority Whip Steny Hoyer, the Democrat's No. 2 leader in the House, told reporters this morning that the inclusion of the controversial Keystone XL pipeline in the bill "undermines any ability to come to a bipartisan agreement."

"This is a stick it in the eye," Hoyer said of the Republicans' intentions. "A clear, politically motivated effort to make this a controversial bill which will appeal to some of their most conservative members who don't give one whit about compromise, as they have demonstrated on a regular basis since January consistently to date."

Majority Leader Eric Cantor said that even though the measure "is not our dream proposal," if the president really does want to keep taxes low for the middle class, "I just would hope that his rhetoric begins to match reality here."

"You can't be for the middle class [and] you can't be for keeping taxes low and be against our Middle Class Tax Relief and Job Creations act," Cantor, R-Va., said "That's what this bill does: [Create] tens of thousands of jobs, if not more. If the president says he wants to protect Social Security and its trust fund from being raided, that's what this bill does as well."

"The president's fond of saying often that in his proposal [The American Jobs Act] are provisions that both Republicans and Democrats support. Well that's exactly what we've got in this bill," he added. "We ask the president to join us and finally putting himself behind this bill that helps the middle class. It's time for the president to compromise as well."