The House Oversight Committee plans to issue a subpoena to Postmaster General Louis DeJoy for documents Democrats claim have been withheld from the panel as it investigates mail delays ahead of the November election.

Chairwoman Carolyn Maloney, a Democrat from New York, issued a memo to members of the committee on Monday declaring her intent to issue a subpoena. The congresswoman also said she was sending a documents request to the Postal Service Board of Governors.