Three Democratic congressmen Thursday asked Vice President Dick Cheney (search) to testify on Capitol Hill about the disclosure of a covert CIA officer's identity, saying "there are many wide-ranging questions about your involvement."

The congressmen asked why Cheney's office was gathering information about Valerie Plame (search), the wife of Bush administration critic Joseph Wilson in 2003; whether the vice president directed his top aide, the now-indicted I. Lewis Libby (search), to speak to the news media about Plame; and whether Cheney was aware Libby was doing so.

The indictment against Libby says he was told by Cheney on June 12, 2003, that Wilson's wife worked at the CIA's counterproliferation division. That was a month before Plame's identity was disclosed by conservative columnist Robert Novak (search).

The congressmen also asked Cheney whether he was aware the administration's claims that Iraq was seeking uranium from the African nation of Niger were false, at a time officials including President Bush were using such assertions as justification for going to war.

The Democrats are Maurice Hinchey of New York, Henry Waxman of California and John Conyers of Michigan. Waxman is the ranking Democrat on the House Government Reform Committee. Conyers is the ranking Democrat on the House Judiciary Committee.

In response, Cheney spokeswoman Lea Anne McBride said that the vice president would cooperate with the Justice Department as the criminal investigation of Special Counsel Patrick Fitzgerald (search) moves forward.

Cheney said following Libby's indictment last Friday that it would be inappropriate to comment on the charges or any facts relating to the proceeding.