(Bloomberg)—President Donald Trump’s administration is recommending the U.S. Postal Service raise prices for shipping packages, a move that would hit online retailers such as Amazon.com Inc., No. 1 in the Internet Retailer 2018 Top 500.

A commission Trump appointed released recommendations for the rate hike Tuesday. Trump appointed the panel after repeatedly criticizing Amazon, which he has accused of bilking the Postal Service. The proposed rate would affect most commercial shippers. Postal Service representatives denied it was losing money on shipping packages for Amazon.

The Postal Service “is on an unsustainable financial path, which poses significant financial risk to American taxpayers,” Treasury Secretary Steven Mnuchin, one of the panel’s members, said in a statement. “Today’s report contains achievable recommendations that fulfill the President’s goal of placing the USPS on a path to sustainability, while protecting taxpayers from undue financial burdens and providing them with necessary mail services.”

Trump appointed the commission after months of intermittent threats and insults against Amazon and the Washington Post, which is also owned by Jeff Bezos, the retail giant’s founder and CEO.

Although the postal service can’t legally deliver packages for less than its delivery costs, Trump has claimed that Amazon was “costing the United States Post Office massive amounts of money for being their Delivery Boy,” a situation that puts “many thousands of retailers out of business.”