By Emelie Rutherford

At least 11 lawmakers–including many outspoken Boeing [BA] backers–want the Pentagon to slow the speed of the revised aerial-refueling tanker competition, saying in a letter too many questions remain about a modified solicitation crafted after auditors faulted the initial effort.

The Pentagon will release a final request for proposals (RFP) for the do-over tanker competition “sometime in the middle of the month,” and then the two offerors will have “about 45 days” to submit their revisions to their earlier proposals, Defense Procurement and Acquisition Policy Director Shay Assad said Aug. 6, when a draft of the new RFP was released. A Pentagon spokesman said yesterday afternoon the timeline Assad described–which culminates with a contract award around New Year’s Eve–still stands.

As of Defense Daily‘s deadline yesterday, though, the new RFP was not yet released.

The Pentagon announced last month it would issue a new solicitation for the Air Force tanker competition after the Government Accountability Office upheld Boeing’s protest of the February tanker contract award to a Northrop Grumman [NOC]-European Aeronautic Defense and Space Co. (EADS) team.

In a letter sent late last Friday, 11 House and Senate members tell Defense Secretary Robert Gates that while they “applauded” his “decisive action” in ordering Pentagon officials to cancel the tanker award and issue a revised RFP, they now fear “the current rush to come to agreement on a revised RFP is putting at risk” the latest opportunity for “a successful decision.”

“In the Pentagon’s rush to initiate an aggressive timeline the most critical component–a clearly defined and understood revised RFP has not yet been fully achieved–which is why we ask that you allow more time for the revised RFP, including the metrics involved, to be vetted by the competitors and briefed to members of Congress,” they write.

They say “many questions remain unanswered,” after congressional staff members were briefed two weeks ago on the draft RFP, including questions about military construction costs for Air National Guard units and states that support the aerial refueling mission.

The letter’s signers are: Sens. Kit Bond (R-Mo.), Patty Murray (D-Wash.), Sam Brownback (R-Kan.), Pat Roberts (R-Kan.), and Claire McCaskill (D-Mo.); and Reps. Norm Dicks (D- Wash.), Todd Akin (R-Mo.), Jo Ann Emerson (R-Mo.), Todd Tiahrt (R-Kan.), Nancy Boyda (D-Kan.), and John Shimkus (R-Ill.), according to a copy provided by Tiahrt.

Since the letter was sent, Boeing and Northrop Grumman executives met over the weekend with Pentagon officials about the new RFP, following earlier meetings held last week.

Boeing backers in Congress have claimed the draft version released Aug. 6 favors Northrop Grumman’s larger proposed aircraft. Rumors have circulated in blogs and news reports that Boeing has considered not submitting a proposal in response to the latest RFP.

Lawmakers’ displeasure with how the Pentagon is handling the revised tanker competition puts its funding in jeopardy. When the House Appropriations Defense subcommittee (HAC-D) marked up its fiscal year 2009 defense appropriations bill on July 30, it included a list of requirements for the tanker competition upon which it says $893 million in funding is contingent. Dicks, the HAC-D vice chairman and one of the letter’s signers, has since criticized the draft RFP.