Amazon.com Inc. filed a lawsuit on Friday challenging the Defense Department’s choice of rival Microsoft for a $10 billion Pentagon cloud-computing contract.

The lawsuit was filed under seal in the U.S. Court of Federal Claims in Washington.

Last month, the U.S. Defense Department decided to award a Pentagon cloud computing contract worth up to $10 billion to rival bidder Microsoft.

Amazon previously said it planned to formally protest its loss of the Pentagon’s Joint Enterprise Defense Infrastructure, or JEDI, cloud contract because the evaluation process was deficient.

In court paperwork, Amazon said the lawsuit was filed under seal because it contains “sensitive” information that “would cause severe competitive harm” if it’s released.

Microsoft asked to intervene in the suit, arguing in a filing that the case will “directly affect Microsoft’s interests” and “carries the potential for significant economic and other harms to Microsoft.”

Amazon will probably argue that its loss of the high-profile contract was due to improper political influence by President Donald Trump. Exhibits filed with Friday’s complaint include Trump’s comments to the press in July as well as a Fox News segment called “Swamp Watch.”

In July, Trump questioned whether the JEDI contract was being competitively bid, citing complaints from Microsoft, Oracle Corp. and International Business Machines Corp. Trump has long criticized Amazon founder Jeff Bezos on everything from the shipping rates his company pays the U.S. Postal Service to his personal ownership of what Trump calls “the Amazon Washington Post.”

Oracle is also appealing a July ruling from the U.S. Court of Federal Claims that dismissed its legal challenge to the cloud contract.