Three senior Democratic lawmakers are demanding that the Department of Justice provide clean copies of all documents relating to the U.S. attorneys investigation, including previously produced copies that had portions blacked out and others that may have been withheld.

In a letter to Attorney General Alberto Gonzales dated Friday, the senators also request that the Justice Department allow the documents to be made public so that they can be used during questioning when Gonzales and other department officials testify to the Senate Judiciary Committee in the coming weeks.

"To date, you have not provided any valid legal basis for your redactions, for your limitations on production or for the restrictions you have unilaterally imposed on their public disclosure," reads the letter signed by Democratic Sens. Dianne Feinstein of California, Patrick Leahy of Vermont and Charles Schumer of New York.

"We are not satisfied by your selective production and unilateral redaction decisions. ... As you know, the committee's upcoming agenda includes authorizing the chairman to issue subpoenas for these documents. We sincerely hope that we can work this out cooperatively," they wrote.

Gonzales is in hot water over his denying that he was involved in the firing of eight U.S. attorneys who allege they were dismissed because of their decisions on whether or not to prosecute politically-tinged cases. The Justice Department argues that the federal prosecutors serve at the pleasure of the president and can be removed from their four-year terms whenever and for whatever cause.

But lawmakers contend that the Bush administration abused its power, written into the updated U.S.A. Patriot Act, to skip the Senate confirmation process for new attorneys and install prosecutors without advice and consent. The Patriot Act provision has since been stripped from the law under legislation passed in both the House and Senate.

In the letter, the senators wrote that "substantial evidence" shows that the removal of Bud Cummins, a U.S. attorney for the Eastern District of Arkansas, was motivated by the decision to install Tim Griffin, an aide to Bush adviser Karl Rove. They added that "officials at the highest levels of the administration intended in bad faith to 'run out the clock'" on Griffin's nomination.

The senators also charge that despite the fact that prosecutors were told they were being removed to make way for other attorneys, Gonzales and others at the department had no replacements in mind for any of the other seven U.S. attorneys who asked to resign.

"Among the issues central to the ongoing inquiry is whether there was a plan to remove otherwise well-performing federal prosecutors, install relatively inexperienced political loyalists, and bypass the Senate's constitutional role in confirming such officials," the senators wrote.