Opening a new front in its battle with the Justice Department, the Senate Judiciary Committee on Thursday will consider authorizing subpoenas for documents linked to the National Security Agency’s warrantless wiretapping program.

The move comes after a May 21 letter in which Judiciary Chairman Patrick Leahy (D-Vt.) and ranking member Arlen Specter (R-Pa.) demanded documents related to the legal opinions and analysis surrounding the controversial program.

The lawmakers asked for a response by June 5 but were rebuffed and are now set to consider authorizing Leahy to issue the subpoenas in a Thursday business meeting. Republicans have the procedural right to block the issuance of the authority for one week, but Specter signed the May 21 letter and it seems unlikely that he personally will object.

Authorizing Leahy to issue subpoenas would be the boldest Congressional move yet to confront the Bush administration over the warrantless wiretapping program.

House Judiciary Chairman John Conyers (D-Mich.) and Judiciary subcommittee on the Constitution, civil rights and civil liberties Chairman Jerrold Nadler (D-N.Y.) also have vowed to consider authorizing subpoenas after a similar letter, and testimony from a top Justice official, yielded no information.

At a hearing of Nadler’s subcommittee last week, Steven Bradbury, the principal deputy assistant attorney general and the head of the Justice Department’s Office of Legal Counsel, said the department would not turn over the documents because of their “confidential nature.”

The move also comes at a time when the White House is seeking support for legislation to expand its wiretapping powers under the Foreign Intelligence Surveillance Act. But Democrats have declared they won’t consider the measure until getting their hands on previous legal opinions.

In their May 21 letter to Attorney General Alberto Gonzales, Leahy and Specter sought a range of documents from 2001 to the present. They include documents pertaining to the president’s authorization and reauthorization of the wiretapping program and any predecessors; “memoranda or other documents” about the legal basis for the program from Justice, the NSA, the Defense Department, the White House or “any other entity within the Executive Branch”; and communications about the program with the Foreign Intelligence Surveillance Court.

“Your consistent stonewalling and misdirection have prevented this Committee from carrying out its constitutional oversight and legislative duties for far too long,” Leahy and Specter wrote.

They added that while much of the information they seek “may currently be classified” that should be “no excuse” for refusing to provide the information to all lawmakers and “select, cleared staff.”

The move comes after the dramatic May testimony of former Deputy Attorney General James Comey before the Senate Judiciary Committee. Comey riveted Senators by giving his account of a hospital bedside visit to then-Attorney General John Ashcroft by then-White House counsel Alberto Gonzales and then-White House Chief of Staff Andrew Card.

Comey related how Gonzales and Card tried to get Ashcroft to approve reauthorizing the NSA program over the legal advice of department officials, including Comey, who served as acting attorney general until Ashcroft recovered. The program was briefly renewed without Comey’s approval but later was adjusted to assuage Justice concerns after Comey and FBI Director Robert Mueller met personally with President Bush. Mass resignations, including those of Ashcroft, Mueller and Comey, were threatened.

Comey’s testimony was an outgrowth of the ongoing probe into the firing of nine federal prosecutors in 2006 . Democrats contend that the U.S. attorneys were fired for improper political reasons and that Justice officials, including Gonzales, have given misleading and shifting explanations about the firing process.

Gonzales insists that nothing improper, or illegal, was done, and Bush has stuck by him in the face of Congressional calls for resignation. Republicans beat back a Democratic-sponsored no-confidence vote on Gonzales this week.