Schiff, a California Democrat, made the demand in a letter to Attorney General William Barr that said his committee had "no choice" but to serve the subpoena after previous efforts , joined by the committee's top Republican, had not led to the Justice Department providing the requested documents. Schiff gave Barr a deadline of May 15 to hand over the evidence.

"The Department's stonewalling is simply unacceptable," Schiff said in a statement Wednesday.

Schiff and Rep. Devin Nunes, a California Republican who's the ranking member of the panel, have previously requested briefings from the FBI and Justice Department on counterintelligence information gathered by Mueller, who investigated possible ties between President Donald Trump's associates and Russia.

The efforts by Schiff and Nunes for information on the counterintelligence probe and its evidence reflected a rare moment of unity between the two top intelligence overseers in the House, who have often otherwise clashed publicly over Trump and the Mueller investigation.

Schiff has argued the counterintelligence information would help the House Intelligence Committee find out if Trump "or the people in his campaign had been compromised," while Nunes has said he was seeking information to find out about the origins of the counterintelligence probe.

In contrast to the joint effort between Schiff and Nunes, the clash between Schiff and Barr added to an ongoing battle between Congress and the Trump administration that now has several fronts, as tensions between House Democrats and the administration ratchet up over demands for documents and testimony. Shortly before Schiff's announcement of a subpoena, House Judiciary Chairman Jerry Nadler, a New York Democrat, declared the broader situation a "constitutional crisis" and his panel voted to hold Barr in contempt.

Schiff said in his statement Wednesday that he would go to court, if necessary, to enforce his subpoena and vowed success.

"The law is on our side," Schiff said. "The committee's efforts to obtain necessary documents to do our constitutionally mandated oversight work will not be obstructed."