Rep. John Doolittle, R-Calif., indicated Thursday he planned to fight a Justice Department subpoena for 11 years of records as part of the Jack Abramoff bribery investigation.

That could set up a lengthy court fight over congressional independence. Rep. William Jefferson, D-La., has been locked in a similar dispute over the FBI's raid on his Capitol Hill office last year. A federal appeals court declared parts of that search unconstitutional, a ruling the Justice Department is challenging.

Prosecutors recently demanded documents from Doolittle and five staffers, the congressman said. The subpoenas seek "virtually every record including legislative records" for the past 11 years, Doolittle's attorney David Barger said in a news release issued Thursday by the congressman's office.

"These efforts raise serious constitutional issues going to the very core of our separation of powers created by the Founding Fathers," Barger said.

The Constitution prohibits the executive branch from using its law enforcement powers to interfere with legislative business. Barger said he and Doolittle would "be vigilant" to ensure Congress' independence is "vigorously protected." Any court challenge would go before a federal judge, but the documents would be sealed.

Prosecutors are investigating connections between Doolittle and Abramoff, the convicted lobbyist. The Abramoff influence-peddling investigation already has netted a dozen convictions, including a guilty plea from one congressman, Bob Ney, R-Ohio, who resigned amid the probe.

"The rest of the Congress would be well served to pay attention to the message the Executive Branch seems to be sending about whether the three branches are truly coequal," Barger said.

Earlier this month, two congressional aides were called before a federal grand jury as part of the Doolittle investigation. The staffers who have been subpoenaed have assured they are merely witnesses, not targets of the investigation, Doolittle said.

In the Jefferson case, the U.S. Court of Appeals for the District of Columbia Circuit held that FBI agents trampled on congressional independence during the raid. Even though they took only documents relevant to their bribery investigation, agents also reviewed legislative documents, which the court said was unconstitutional.

That ruling has already caused impeded ongoing investigations, Justice Department attorneys indicated in court documents recently. Some members of Congress interpret the ruling as prohibiting FBI agents from interviewing congressional staffers attorneys wrote.

Cooperative legislative aides have played key roles in the prosecution of public officials in the Jack Abramoff lobbying scandal.