A backlash erupted last night over a decision by the US Air Force to award a $35-billion contract to a partnership that includes the European parent of Airbus.
Artist's rendition provided by Northrop Grumman shows an aerial tanker refuelling an F-18 fighter.
US Speaker of the House Nancy Pelosi, a California Democrat, said the deal posed "serious questions that Congress must examine thoroughly."
Unions representing US aerospace workers raised questions about Airbus parent EADS and criticising the Air Force for not considering US jobs in its decision.
As Air Force officials met with angry members of Congress, presidential candidate Hillary Clinton said in a statement: "I am deeply concerned about the Bush administration's decision to outsource the production of refuelling tankers."
She said it was "troubling" that the contract would go to "a team that includes a European firm that our government is simultaneously suing . . . for receiving illegal subsidies."
EADS - with major manufacturing facilities in France and Germany - teamed up with US aerospace group Northrop Grumman to outbid Boeing for the job, which will bring with it thousands of high-paying jobs over many years.
The Air Force plans to buy 179 aircraft over 15 years to replace aging KC-135 tankers, which were built by Boeing.
A bipartisan group of lawmakers last night wrote Defense Secretary Robert Gates and demanded that the Air Force tell Chicago-based Boeing this week why it lost rather than wait until mid-March as planned.