House Judiciary Committee aides confirmed Tuesday morning that former Attorney General John Ashcroft and ex-Justice Department lawyer John Yoo have agreed to voluntarily testify before their committee.

An agreement with Yoo did not come to fruition until late Monday afternoon, the aides said.

On Tuesday morning, the House Judiciary Subcommittee on Constitution, Civil Rights and Civil Liberties, chaired by Rep. Jerrold Nadler (D-N.Y.), authorized, but did not issue, a subpoena for the testimony of David Addington, chief of staff to Vice President Cheney.

That means that Judiciary Chairman John Conyers (D-Mich.) now has the power to issue the subpoena to Addington whenever he chooses.

The details of Yoo’s testimony are still being negotiated, said Judiciary aides, and it is unclear when Yoo and Ashcroft will appear before the committee. Yoo is now working as a law professor at the University of California at Berkley.

Yoo is the former deputy assistant attorney general who wrote the controversial March 2003 memo that authorized the use of harsh interrogation tactics to elicit information from terrorist detainees held overseas.

Conyers invited Yoo to testify on April 8.

— Rachel Van Dongen