Connecticut Sen. Richard Blumenthal, the top Democrat on the Homeland Security Committee’s Permanent Subcommittee on Investigations, has issued warning letters to Homeland Security Secretary Markwayne Mullin, Federal Communications Commission Chairman Brendan Carr and cryptocurrency companies linked to Trump.

Blumenthal issued the notices Thursday, asking the recipients to produce records by Jan. 4, the day after the new Democratic majority is sworn in. If they do not comply, Blumenthal wrote, the panel will be left with “no choice but to consider alternative measures to obtain compliance.”