The House committee investigating last year’s attack on the U.S. Capitol voted to subpoena Donald Trump, a dramatic challenge to a former president just weeks before Republicans and Democrats face off in an election that will determine control of Congress.

The committee, in a unanimous vote on Thursday, agreed to demand documents and testimony from Trump about his role in the Jan. 6 attack.

A subpoena likely wouldn’t force immediate testimony from Trump, who has a record of using extensive maneuvers to delay legal proceedings. But it’s an escalation of the committee’s demands to hold Trump accountable for his actions surrounding the assault.