House Oversight and Government Reform Chairman Trey Gowdy received a document dump from top Senate and House Democrats Monday, urging the South Carolina Republican to go deeper in his investigation of Environmental Protection Agency Administrator Scott Pruitt for abuses of power.

“These new documents raise serious questions about EPA’s security expenditures,” the Democrats told Gowdy in a letter focused on Pruitt’s $43,000 secure phone booth.

“In our view, the documents provided to us may constitute evidence of a ‘violation of law, rule, regulation, gross mismanagement, a gross waste of funds, an abuse of authority, or a substantial and specific danger to public health or safety,’" the Democrats wrote, citing federal rules governing personnel management and proper administrative procedure.

The letter was signed by Sen. Tom Carper, the top Democrat on the Environment and Public Works Committee, and Rep. Elijah Cummings, the top Democrat on Gowdy’s Oversight and Government Reform Committee, among other lawmakers from both chambers.

At the minimum, the new documents should encourage Gowdy to request more documents from the EPA on Pruitt’s security booth, the Democrats wrote. They say the documents raise questions about the level of privacy the booth provides Pruitt, especially when involving classified communications.

“Documents provided to us from within EPA indicate that as of March 2017, the administrator’s office was not cleared for classified communications,” the letter stated.

“The phone booth, which was installed months later, appears to be a ‘privacy booth’ installed by a vendor that describes itself as a ‘manufacturer and distributor of acoustical products’ whose mission is ‘to solve sound and noise control problems to improve every environment of your life.’”

The Democrats want the nonclassified documents they obtained to build on a report issued last week by the Government Accountability Office that showed Pruitt’s booth violated federal disclosure laws because the agency did not advise Congress about the $43,000 expense.

“While GAO drew ‘no conclusions regarding whether the installation of the privacy booth was the only, or the best, way for EPA to provide a secure telephone line for the administrator,’ we believe that to be an important topic for further investigation by Congress,” it added.

“Given the latest developments and these new documents, we believe these and related matters are ripe for additional document requests to EPA, and that Administrator Pruitt should testify about all of these matters immediately,” the Democrats concluded.

The Democrats also want Gowdy to look more closely into Pruitt’s security chief. Pasquale “Nino” Perrotta, as well as Edwin Steinmetz, a partner with Perrotta at the Sequoia Security Group.

Steinmetz was contracted to conduct a security sweep of Pruitt’s office before the booth was installed.

“We have been informed that this contract may have been paid for through the use of an EPA credit card without first obtaining the required pre-approval,” the letter said. In addition, EPA officials with the homeland security office said the sweep wasn’t thorough enough.

The letter was sent as Bloomberg reported that White House officials told Republicans to temper their defense of Pruitt.