A US congressional panel investigating the Bush administration's domestic spying program has subpoenaed documents from the White House, Vice President Dick Cheney's office, the National Security Council and the Justice Department.
Senate Judiciary Committee Chairman Patrick Leahy issued the subpoenas for Bush administration documents after his Democratic-led panel failed to get the papers it was seeking despite a series of requests.
The documents relate the warrantless surveillance of people inside the United States with suspected ties to terrorists. The program was authorised by President George W. Bush shortly after the September 11 attacks and became public in 2005.
In a letter accompanying the subpoenas, Leahy wrote: "Over the past 18 months, this committee has made no fewer than nine formal requests to the Department of Justice and to the White House, seeking information and documents about the authorization of and legal justification for this program."
"There is no legitimate argument for withholding the requested materials from this committee," Leahy wrote. "The administration cannot thwart the Congress's conduct of its constitutional duties with sweeping assertions of secrecy and privilege."
With the authorization of the full Democratic-led committee, Leahy issued subpoenas to the White House, office of Vice President Dick Cheney, the Justice Department and the National Security Council.
Leahy's committee authorized the subpoenas last week, drawing a swift response from the White House that the documents were off limits and highly classified.
Bush could challenge the subpoenas, citing a right of executive privilege his predecessors have invoked with mixed success to keep certain materials private and prevent aides from testifying.
Critics charge the program, conducted by the National Security Agency, violated the 1978 Foreign Intelligence Surveillance Act, which requires warrants. Bush said he could act without warrants under wartime powers.
In January, the administration abandoned the program and agreed to get approval of the FISA court for its electronic surveillance. Bush and Democrats still are at odds over revisions he wants in the FISA law.