As the Cardiac Congress scrambles to meet its final deadlines and wrap up a contentious 12-month legislative session, House Speaker John Boehner guaranteed that a controversial pipeline will be part of a year-end jobs package, even as Democrats work today to strike the measure from the bill.

The Senate is expected to act on the jobs package this weekend, but Democrats in the upper chamber prefer to pass a short-term, two-month extension without the Keystone XL Pipeline, a modification the speaker strongly resisted.

"The House has done its work. We're waiting on the United States Senate," Boehner, R-O hio, told reporters after meeting with his rank and file. "But these rumors that are floating around here about a two-month extension - I'll just say this: If that bill comes over to us [without the pipeline], we will make changes to it, and I will guarantee you that the Keystone Pipeline will be in there when it goes back to the United States Senate."

After the so-called "megabus" appropriations bill passes, the final piece of legislation Congress must approve before the end of the year is the payroll tax credit extension, which the House passed Tuesday in a package tied to unemployment insurance; the SGR Doc Fix (allowing Medicare reimbursement payments to doctors to stay at current levels); and the Keystone XL Pipeline, a $7 billion project that will pump tar sands from Canada to refineries in Texas.

The provision would accelerate the timing of President Obama's decision to move ahead on the pipeline to within 60 days of passage, a mandate the president warned would lead to a presidential veto. One senior Republican aide who attended the conference meeting today said that when Boehner told the GOP conference of the House's position on the pipeline, the entire conference burst into cheers.

Democrats have resisted the pipeline over concerns that the public has not had an adequate opportunity to comment on the project. Last month the president delayed a decision on whether to move forward until late next year. 

Today the speaker repeatedly promised that if Senate Democrats attempt to strike the pipeline, the House will add it back.

"How much clearer can I be?" Boehner answered when asked to clarify his ultimatum. "All I'm going to tell you is, we will make changes to that bill, and I'll guarantee you the Keystone Pipeline will be in the bill when it goes back to the United States Senate."

Faced with the speaker's ultimatum, House Minority Leader Nancy Pelosi declined to make her own assurance about excluding the pipeline from the final package.

"Right now the two leaders in the Senate … are working on what that bill might look like. When we see it, I'll have a comment on it," Pelosi, D-Calif., said. "I hoped that it would be finished around now so … it could be written up and voted upon one way or another tomorrow. But again, until I see the bill I'm not going to comment on it."

Boehner said that after the House passes the omnibus spending bill this afternoon, lawmakers will leave town while the Senate votes on the omnibus and then tweaks the House-passed jobs bill.

Senior Republican aides indicated that the House could be amicable to some changes to the jobs package, like pulling a drug testing requirement from unemployment insurance reform.

But without the pipeline, House Appropriations chairman Harold Rogers said the bill is dead-on-arrival in the House.

"I would imagine that if the Senate sends over a bill that does not include the pipeline that it would be defeated here," Rogers, R-Ky., predicted. "It has to include the pipeline."

Boehner credited Rogers for negotiating a bipartisan omnibus spending package, which bundles together nine appropriations bills to fund the government through the end of the fiscal year. Although the speaker said he was "not going to describe it as perfect," Boehner boasted that the bipartisan negotiations were "certainly a process that we haven't seen for a number of years."

"This will mark for the second year in a row that we will spend less money on the operation of our government - two consecutive years that we've cut spending," he said. "We also take steps in this bill to stop some of the excessive regulations that are harming our economy, and for the first time in modern history there are no earmarks in this bill."