WASHINGTON — Two key lawmakers are calling for an investigation into whether the Pentagon tilted its high-stakes $10 billion cloud computing solicitation to favor Amazon.

House appropriators Tom Cole, R-Okla., and Steve Womack, R-Ark., sent a letter Oct. 22 to the Department of Defense’s inspector general to voice concern that the government’s requirements for the Joint Enterprise Defense Initiative cloud program appeared tailored “to one specific contractor.”

While the Seattle-based e-commerce and cloud computing giant isn’t mentioned by name, the concerns are understood to be about Amazon Web Services, a strong contender to win the contact after Alphabet’s Google withdrew from the competition.

Amid the likelihood the Pentagon will award a such a large chunk of the defense cloud market to a single provider, there have already been formal protests to the Government Accountability Office from IBM and Oracle. (Microsoft has announced a cloud service expansion.)

IBM’s Sam Gordy said in a statement earlier this month that the Pentagon’s single-source strategy runs counter to industry’s “multi-cloud direction because of security, flexibility and resilience."

“JEDI’s primary flaw lies in mandating a single-cloud environment for up to 10 years,” he said, adding: “JEDI’s single-cloud approach also would give bad actors just one target to focus on should they want to undermine the military’s IT backbone.”

In the lawmakers' letter, they seemed to echo that line of thinking, arguing the JEDI solicitation’s structure and select provisions “run contrast to industry best-practices and federal acquisition guidelines."

“Of particular concern are the ‘gating’ or restricting provisions and the structure of the proposed contract, that seem to be tailored to one specific contractor,” they wrote.

They also pointed to the inclusion of DoD officials who “have significant connections to the specific contractor,” which they say contradicts federal acquisition regulations and Pentagon ethics policies.

A former senior aide to Defense Secretary Jim Mattis, Sally Donnelly, previously consulted for Amazon Web Services, though Donnelly’s camp has denied she exercised influence over the matter.

The letter is the latest hiccup for Pentagon officials overseeing JEDI’s development and execution, who continue to take heat from industry, former officials, Congress and other stakeholders.

The Pentagon appropriations package passed last month included a restriction on JEDI funding until 90 days after Pentagon officials submit a plan to account for cloud services and a strategy for incorporating multiple-award prospects.

In a discussion with reporters in August, the Hudson Institute’s William Schneider called the congressional restrictions “a speed bump” in the process of moving ahead with JEDI.

Womack chairs the House Budget Committee and Cole chairs the House Appropriations Subcommittee on Labor, Health, Human Services and Education.