Before the Supreme Court rules on the issue, congressional Republicans included a provision in the mammoth spending bill to keep the government from releasing the names of gun shops and gun owners whose weapons were used in crimes.

The provision, written by Rep. George Nethercutt, R-Wash., was a part of the House version of the spending bill for Treasury and postal operations and made it into the final $397.4 billion package for the fiscal year ending Sept. 30. It prevents the Bureau of Alcohol, Tobacco and Firearms from spending money to release the data.

The Supreme Court is to hear arguments March 4 on how much information the ATF should be required to release about the 200,000 firearm traces conducted annually, in which police trace a weapon used in a crime to determine who made it, sold it and bought it.

As of now, the agency releases the make, model and serial numbers of the guns after a waiting period, but it does not identify the weapon's buyers and sellers. The ATF also tracks people who buy several guns in a week but also refuses to release those names.

The city of Chicago, one of the municipalities suing the gun industry for damages related to gun violence, requested the names of buyers and sellers under the federal Freedom of Information Act. The 7th Circuit Court of Appeals backed the city, but the Bush administration, backed by the National Rifle Association and the 300,000-member Fraternal Order of Police, appealed to the Supreme Court.

ATF spokesman Andrew Lluberes said the agency is looking at the congressional provision to see if it has to stop giving out any data about weapon traces, including the makes, models and serial numbers.

The court case involved the names of buyers and sellers. The Bush administration and its supporters contend those should remain confidential to protect crime investigations and gun owners' privacy. Opponents say releasing the records would let the public know whether only a few gun dealers are responsible for selling most of the weapons found at crime sites.

"This data must remain protected to ensure the integrity of criminal investigations, but unfortunately a recent U.S. Circuit Court decision could compel law enforcement agencies to disclose this data, contrary to Freedom of Information Act law, privacy protections and Supreme Court precedent in this area," Nethercutt said. "This amendment is the only alternative to jeopardizing thousands of criminal cases."

NRA spokesman Andrew Arulanandam praised Congress' action. "We support efforts at every level to protect the privacy of law-abiding gun owners," he said.

The NRA has been a strong financial supporter of the Republican Party. Since Jan. 1, 2001, the lobby for gun owners' rights has contributed $1.9 million to federal candidates and the political parties, 92 percent of it to the GOP, according to the Center for Responsive Politics, a nonpartisan research group. The NRA gave $50,000 to the National Republican Congressional Committee in October, right before the November elections that saw the GOP increase its majority in the House.

The pro-gun control Brady Campaign to Prevent Gun Violence, formerly Handgun Control, criticized the congressional action.

"Giving ATF such special treatment only serves to protect crooked gun dealers and to prevent victims of gun violence from seeking justice," said Michael Barnes, president of the Brady Campaign.