WASHINGTON (CNN) -- The White House must release its visitor logs and cannot hide behind a shield of privilege, a federal judge ruled Monday. The Bush administration has resisted public disclosure while it fights a lawsuit over alleged political influence by conservative Christian leaders.

The Bush administration has been fighting the release of White House visitor logs.

U.S. District Court Judge Royce Lamberth concluded the information is part of the public record and is subject to disclosure under the Freedom of Information Act as "agency records."

"Because the Secret Service creates, uses and relies on, and stores visitor records, they are under its control," said Lamberth.

He ordered the Secret Service to produce records within 20 days.

The White House claimed exclusive control of the documents, subject to the complete discretion of the president over their release.

Secret Service records have been an important tool for advocacy groups and members of Congress seeking information on the inner workings of the executive branch.

Congressional investigators used the records a decade ago in their investigations of the various Whitewater scandals involving President Clinton and his associates, as well as allegations of influence peddling by the Clinton campaign in the 1996 elections.

Citizens for Responsibility and Ethics in Washington, a self-described government watchdog group, sought the visit records of prominent conservatives James Dobson of Focus on the Family, Wendy Wright of Concerned Women of America and seven others including the late televangelist Jerry Falwell.

"CREW is pleased that the judge saw through the White House's transparent attempts to hide public documents from the American people," said Melanie Sloan, the group's executive director. "We look forward to sharing the documents we obtain through this lawsuit."

The White House and Justice Department had no immediate reaction to the ruling.

Separate legal action by CREW and other groups, including Judicial Watch and the Washington Post, sought White House visitor logs that listed lobbyist Jack Abramoff. He pleaded guilty last year to public corruption charges.

The White House and the Secret Service in 2006 signed an agreement that visitors to the White House complex were not subject to public disclosure. That "memorandum of understanding" was disclosed during legal action over the Abramoff records.

Lamberth called that a "self-serving" agreement because it was issued after the records were created and after the CREW lawsuit.

The judge, in a separate ruling Monday, said he lacked the authority to order the Secret Service to stop destroying its visitor records once copies were turned over to White House officials. But Lamberth noted the National Archives had to approve any destruction of the logs.

Another federal judge in Washington ordered the release of Secret Service logs of visitors to Vice President Dick Cheney's office. Cheney claimed those logs were subject to executive privilege. That ruling is being appealed.

Lamberth noted the Secret Service has an important "protective mission" when compiling electronic information -- including background checks -- of those seeking to enter the White House complex. But he said the agency's claim of "limited use" of the data does not mean the records are not subject to judicial review.

"This does not mean the Secret Service does not read or rely on them," wrote Lamberth. "If that were the case, any convenience store patron who has ever bought a losing scratch ticket could claim they did not gamble simply because they held the ticket for only a few minutes."

The issue of White House privilege over visitor logs has not been fully addressed by the Supreme Court.

The case decided Monday is Citizens for Responsibility and Ethics in Washington v. U.S. Department of Homeland Security. E-mail to a friend

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