The court declined to review an appeals court ruling that the FBI reviewed legislative documents in the office of Rep. William Jefferson, D-La., in violation of the Constitution.
Jefferson has pleaded not guilty to charges of soliciting more than $500,000 in bribes while using his office to broker business deals in Africa. His trial has been delayed indefinitely.
While the Bush administration asked the Supreme Court to intervene, Attorney General Michael Mukasey said last month that he would prefer Congress and the Justice Department reach agreement about any future searches.
The ruling "is jeopardizing ongoing public corruption investigations," the Justice Department said in urging the justices to accept its appeal.
If allowed to stand, the ruling also would essentially prevent investigators from searching lawmakers' offices because it requires the FBI to give the lawmakers advance notice, the department said.
"The bottom line is that, if the government cannot search a member's office in the manner authorized by the search warrant here ... the government cannot do so in any meaningful manner and congressional offices may become a 'sanctuary for crime,"' the Justice Department said.
Yet Mukasey said in testimony to Congress that an agreement between lawmakers and his agency would be better than a court-issued "bright-line ruling that one of us can't live with or would find it awkward to live with."
At issue is a constitutional provision known as the speech or debate clause, which protects elected officials from being questioned by the president, a prosecutor or a plaintiff in a lawsuit about their legislative work.
The question for the court was whether the protection also applies to searches.
The U.S. Court of Appeals for the District of Columbia Circuit said it does.
The appeals court did not say lawmakers would need to have advance notice of the FBI's arrival. Rather, the court said the Justice Department can't broadly review legislative records. One solution mentioned in the opinion was for FBI agents to lock down the office, then allow the lawmaker to set aside disputed documents. A judge would decide whether the records could be seized.
Officials said they took extraordinary steps - including using an FBI "filter team" not involved in the criminal case - to review the congressional documents. Government attorneys said the Constitution was not intended to shield lawmakers from prosecution for political corruption.
Prosecutors have said they can proceed to trial without waiting for the contested documents.
The indictment against Jefferson alleges that he received more than $500,000 in bribes and demanded millions more between 2000 and 2005, including $90,000 he received from an FBI informant that was later found in the freezer of his Washington home.
Prosecutors contend he used his influence as chairman of the congressional Africa Investment and Trade Caucus to broker deals in Nigeria, Ghana, Cameroon and other African nations on behalf of those who paid bribes to him.
The case is U.S. v. Rayburn House Office Building, Room 2113, 07-816.