WASHINGTON, D.C. (WIBW)_ A letter to the Pentagon is urging the Defense Dept. to reject any lobbying efforts by a potential competitor to Boeing for a multibillion dollar refueling tanker contract.

The letter was co-signed by Sens. Sam Brownback and Pat Roberts (R-KS) as well as Rep. Todd Tiahrt (R-Goddard).

They're concerned about efforts by Airbus to get the deadline extended, affording the European airplane manufacturer time to find a new partner with which it can submit a bid. Originally, the company had been teamed with Northrop Grumman, but they withdrew from the competition earlier this month.

The Kansas delegation argued if a prospective competitor cannot meet the military's deadlines and requirements, the Air Force should not hesitate to award the contract to an American company ready to build tankers on its schedule.

Read the full text of the letter below:

Dear Secretary Gates:
We are concerned by multiple reports of lobbying by foreign governments and EADS to extend the deadline for accepting bids for the KC-X aerial refueling tanker competition. We hope that these reports are inaccurate and that the Department of Defense (DoD) will not consider altering this competition to address the narrow interests of a foreign power.

On several occasions DoD officials have stated that the tanker is a top acquisition priority. The effort to replace the Eisenhower-era fleet of KC-135 refueling tankers has already been protracted. We agree, which is why we believe that pushing back the bid deadline is unacceptable.

The Department of Defense has gone to great lengths to ensure a fair competition. Changing deadlines would undermine this effort. Companies should choose to bid based on the terms provided and not expect DoD to change the rules in the middle of the game.

Meeting the deadline is one of the requirements of the RFP. If a prospective competitor cannot meet deadlines and requirements, the Air Force should not hesitate to award a contract to an American company whose workers stand ready to build tankers on the Air Force's schedule.

We also are aware that several European officials seem to suggest that failure to change the military requirements to meet the capabilities of the EADS aircraft is protectionism. We hope you will stand firm and defend the validated requirements found in the Request for Proposal (RFP). As you know, foreign competitors are allowed to bid for U.S. defense contracts, and have seen great success in recent years. In fact, we are concerned the Department of Defense has gone too far in supporting foreign competitors by ignoring illegal subsidies and failing to equally apply costly regulations. To suggest, however, that DoD should alter the RFP to ensure a foreign competitor will bid or is successful is outrageous and inappropriate. The Department of Defense has a responsibility to the warfighter, not foreign nations or companies. We hope that DoD will reject these attempts at diplomatic intimidation.

Companies should not be led to believe that they can engage in sole source blackmail to manipulate the procurement process, yet that is exactly the impression DoD would give if it extends the bid deadline. We see no reason for delay, and we urge the Department to do everything possible to accelerate the timetable for new tankers to reach the warfighter.