WASHINGTON -- When the U.S. Air Force at last reveals the winner of a $40 billion contract for aerial refueling tankers, it won't merely mark a turning point in one of the more tortuous chapters in Pentagon procurement history.

It also would help determine the fate of the American economy, its industrial base and national security.

That's according to a quintet of senators from three states who are pushing hard for a victory by Boeing.

During a press conference at the U.S. Capitol on Thursday, Sen. Patty Murray led an argument by a bipartisan group of lawmakers that awarding the tanker deal to the European parent of Airbus would deprive Americans of much-needed jobs.

Boeing has claimed that if the tankers are built with a military version of its 767 jetliner, it would support 50,000 U.S. jobs, including 11,000 in Washington state. Airbus parent EADS counters that a win for the larger Airbus A330 tanker would support 48,000 American jobs. Airbus plans to assemble the tankers in Mobile, Ala., with component parts made in Europe.

"If we are going to win the future, we are going to need to win this contract," Murray said. "We are doing this to remind the administration and the country what's at stake."

Underscoring that message, the press conference room was festooned with signs proclaiming "American jobs on the line" and "Support American aerospace."

Also appearing at the event were Sens. Maria Cantwell of Washington and Pat Roberts and Jerry Moran, both Republicans of Kansas, a major Boeing manufacturing center. A fifth senator, Debbie Stabenow, is from Michigan, where Boeing currently employs 22 people but hopes to gain 450 more jobs with a tanker contract.

The Air Force has been trying for a decade to replace its aging KC-135 refueling aircraft. Its 2001 decision to lease 100 tankers from Boeing was scotched after revelations that the company's chief financial officer offered jobs to a Pentagon acquisitions officer and her family. A subsequent tanker award to Northrop-EADS was successfully challenged by Boeing on grounds that the competition was flawed.

Further roiling the process, the World Trade Organization has recently ruled that Airbus -- and to a lesser degree, Boeing -- has benefited from billions of dollars in illegal government subsidies. Boeing partisans on Capitol Hill have argued for penalizing EADS, something the Pentagon has refused repeatedly.

The decision for this third round is expected to hinge on price. Aerospace analysts have speculated that EADS likely would prevail on that score. The Air Force is expected to name the winner shortly.

Asked if all the political interference might further delay the Air Force from upgrading its equipment, Moran said that's why the Pentagon must ensure that its latest choice of a winner "has to be absolutely, above-board correct."