Lawmakers used a new spending bill introduced March 21 to raise concerns about the Department of Defense’s current approach to buying new cloud computing services through a single multibillion dollar contract.

Congress wants the secretary of Defense to provide two reports on the DoD’s cloud acquisition program, known as Joint Enterprise Defense Infrastructure (JEDI), to justify the program’s contract format, duration, and cost.

The JEDI program has been controversial almost since it was announced because it aims to transform the Pentagon’s IT system through a single, multibillion-dollar 10-year award rather than awarding several companies work on the program. Many industry leaders argue that the broad scope of the single contract leaves only a handful of companies capable of meeting the requirements. Lawmakers shared those worries.

“There are concerns about the proposed duration of a single contract, questions about the best value for the taxpayer, and how to ensure the highest security is maintained,” reads the draft of Congress’ omnibus appropriations bill.

Pentagon officials have stressed that a single-award contract is the most effective and secure way to transition Defense Department data to the cloud.

“We believe that a multiple-award cloud would exponentially increase the overall complexity,” Tim Van Name, deputy director of the Defense Digital Service, said at a March 7 JEDI cloud industry day. “The systems in different clouds, even when designed to work together, require complex integration, which raises the bar for the development, testing and ongoing maintenance.”

The first of the two reports Congress requested would require Defense Secretary Jim Mattis to submit a justification of the recent solicitation for cloud services issued under the JEDI program. Specifically, lawmakers are asking for confirmation that all of the relevant defense experts and agencies were consulted in the drafting of the formal document.

The second report would explain the Pentagon’s decision to execute a single cloud-servicing contract “rather than creating an infrastructure capable of storing and sharing data across multiple cloud computing service providers concurrently.”

Defense Department officials have said they hope to have the final solicitation for the contract posted in May with a contract award date expected in September.