Rep. Elijah Cummings (D-MD), the ranking member on the House Oversight Committee, on Wednesday called on the committee’s chair, Rep. Trey Gowdy (R-SC), to subpoena the White House and 16 federal agencies for documents on Trump administration officials’ use of personal email.

Gowdy and Cummings asked the White House and other federal agencies in September to identify any staffers who used a personal email account to conduct official business. The request followed reports that several administration officials, including President Donald Trump’s son-in-law, Jared Kushner, had used their personal email accounts to conduct work for the White House.

The White House ignored the Oversight Committee leaders’ request, however, and 16 of the 25 agencies the congressmen contacted also failed to comply with the request, according to Cummings.

“Although we sent a joint request to the White House last September seeking a wide range of documents, you abruptly abandoned our investigation after the White House informed us that they had their own internal review underway,” Cummings wrote in the letter calling on Gowdy to subpoena the White House.

Cummings argued that Gowdy took a different approach when investigating former Secretary of State Hillary Clinton’s private email use.

“You demanded—and I supported—the production of all her emails related to Benghazi, and you did not wait for the Inspector General of the State Department to complete their own internal reviews. You repeatedly called for an independent security review of her emails, and you showcased her use of private email as a potentially serious breech of national security. As a result, many Republicans—including President Trump and his National Security Adviser Michael Flynn—used this as a rallying cry to call for criminal penalties,” Cummings wrote.

“In contrast, since President Trump assumed office, you have refused to insist on the production of documents we both requested five months ago, you have refused to request a security review of private emails, and you have refused to request even single email from Mr. Kushner or anyone else at the White House, despite the fact that they apparently violated federal law,” he added.

Read Cummings’ email calling for Gowdy to subpoena the White House: