(CNN) The House select committee investigating the January 6, 2021, US Capitol attack voted to subpoena former President Donald Trump for documents and testimony during a high-profile public hearing Thursday.
The unanimous vote marks a significant escalation by the panel that will set up a showdown with the former President. It is not expected that Trump will comply with the subpoena, but the action serves as a way for the committee to set down a marker and show that it wants information directly from Trump as the panel investigates the attack.
The vote took place at the end of Thursday's hearing, as the panel made a case to the American public ahead of the midterm election that Trump lied about the outcome of the 2020 election and spurred on a violent mob of his supporters to attack the Capitol.
"It is our obligation to seek Donald Trump's testimony," the panel's chair, Rep. Bennie Thompson, a Mississippi Democrat, said ahead of the subpoena vote during the hearing.
"The need for this committee to hear from Donald Trump goes beyond our fact finding," he said. "This is a question about accountability to the American people. He must be accountable. He is required to answer for his actions. He is required to answer to those police officers who put their lives and bodies on the line to defend our democracy. He is required to answer to those millions of Americans whose votes he wanted to throw out as part of his scheme to remain in power."
The subpoena will surely trigger a prolonged court battle over Trump's possible compliance, which could even outlast the committee itself. Republicans have pledged to shut down the Democratic-run panel if they retake the House majority in the midterm election next month.
Trump has previously derided the panel as an "Unselect Committee of Political Thugs and Hacks" and said its members are "evil, sinister and unpatriotic." He has also complained that the committee's "partisan kangaroo court" proceedings have "allowed no due process, no cross-examination and no real Republican members of witnesses to be present or interviewed."
At the beginning of the hearing, Thompson announced that the committee had changed Thursday's public hearing to a business meeting, which is a technical difference but meant that the committee could vote on investigative actions.
"There is precedent in American history for Congress to compel the testimony of a president. There is also precedent for presidents to provide testimony and documentary evidence to congressional investigators. We also recognize that a subpoena to a former president is a serious and extraordinary action -- that's why we want to take this step in full view of the American people," Thompson said ahead of the vote, warning that the stakes are high for "our future and our democracy."
Thursday's hearing is expected to be the final one before the midterm elections.
This story has been updated with additional developments.