Under federal law, Presidential appointees are allotted $5,000 to decorate their offices, unless Congress is notified in advance about a higher level of spending. Pruitt exceeded the allotment without notifying Congress, the GAO determined, thereby violating the Financial Services and General Government Appropriations Act and the anti-deficiency act.

The EPA did not immediately respond to request for comment; the organization had said that the phone booth should not be included as part of office decorations, a claim the GAO rebutted in its report.

“EPA’s statements place the privacy booth squarely within the meaning of “furnish,” as the booth equipped the office with something that EPA asserts it needed. Accordingly, section 710 [of the Financial Services and General Government Appropriations Act] applied to this obligation and EPA was required to notify the appropriations committees of its proposed obligation,” Thomas Armstong, the GAO’s General Counsel wrote in a letter to Democratic lawmakers on Monday.

Pruitt has come under scrutiny for his extravagant spending habits in recent weeks, after reports emerged that he had subverted the White House by giving salary raises to his favorite aides — which he has denied any involvement in — and the cost of his travel.

Last week, Democratic lawmakers sent letters to both Pruitt and President Trump with new allegations from a former aide to Pruitt, Kevin Chmielewski, who told lawmakers Pruitt purchased bulletproof vests and weapons in the name of enhanced security, and based his travel plans on incurring frequent flyer miles or visiting his home state of Oklahoma. The lawmakers requested documents from Pruitt that would confirm these allegations.

“The new information provided by Mr. Chmiewelski, if accurate, leaves us certain that your leadership at EPA has been fraught with numerous and repeated unethical and potentially illegal actions on a wide range of consequential matters that you and some members of your staff directed,” the lawmakers wrote to Pruitt.