IN A SERIES of stealth measures and after private communication with the gun lobby, Attorney General John Ashcroft is quietly taking steps to erode the very gun laws he has sworn under oath to defend. All law-abiding Americans should be deeply concerned about Ashcroft's efforts to undermine the existing Brady Law's criminal background check system and dramatically reverse longstanding Justice Department measures to keep guns out of the hands of those who pose the greatest risk to safety and security. We urge the attorney general to reverse the course he is taking and to live up to the commitments he made during his Senate Judiciary Committee confirmation hearings.

Last January, during those confirmation hearings, Ashcroft conceded that he personally disagrees with some of the nation's gun laws. This disclosure was no surprise to most of us who had served with him while he was a senator. However, in response to direct questions about whether he would attempt to reverse or urge a new interpretation of existing gun laws, he said his personal disagreements with those laws would in no way affect his commitment to upholding them. ''As attorney general, it's not my judgment to make that kind of call about the relative merit of gun laws,'' he testified. ''My responsibility is to uphold the acts of the legislative branch of this government in that arena.'' A majority of the Senate accepted his commitment, and he was confirmed by a vote of 58 to 42.

Only six months after those confirmation hearings, it appears that Ashcroft is backing off his commitment. On May 17, he sent a letter to the National Rifle Association contending that the Second Amendment confers an individual right to own guns, not just a collective right to a well-regulated militia.

As support for this contention, he cited four Supreme Court decisions from the 1890s but failed to mention the court's leading decision in 1939 that is clearly contrary to his position.

Moreover, Ashcroft's interpretation of the Second Amendment is diametrically opposed to that currently being advanced by the Justice Department in the pending case of United States v. Emerson, where the department has advanced the position that gun ownership is a collective, not individual, right.

In his letter to the NRA, Ashcroft also articulated a new standard for evaluating gun laws, proposing to require that any restriction on gun ownership be supported by a compelling state interest - a test that very few laws can survive. Even law professors who otherwise agree with the individual-rights theory acknowledge that the Constitution permits the reasonable regulation of guns. Ashcroft's new Second Amendment theory, however, will strengthen the hand of the NRA and other foes of gun control.

Immediately after we became aware of Ashcroft's letter to the NRA, we wrote to him, asking him to reconsider the changes in gun control policy he was advocating. He has not responded.

Shortly afterwards, two public policy groups, the Brady Campaign and Common Cause, filed an ethics complaint against the attorney general, charging that his letter to the NRA constitutes an ethical breach because it conflicts with the official position of the United States in the Emerson case. According to Samuel Dash, an expert in legal ethics, the attorney general's letter to the NRA constitutes an act of disloyalty to his client, the United States, and an impermissible conflict of interest.

We have also learned that the Justice Department's Office of Legal Counsel is drafting an opinion to make the attorney general's views on the Second Amendment official policy of the government. This would be a radical departure from its longstanding position.

Ashcroft's antipathy to sensible gun control is also demonstrated by his recent decision to require the immediate destruction of records gathered under the National Instant Background Check System. This is the system used to conduct background checks of gun purchasers under the Brady Law. Current regulations require the FBI to retain these records for 90 days. Eliminating this needed would eviscerate the ability of law enforcement officials to prevent fraud and illegal gun sales by unscrupulous dealers to straw purchasers, convicted felons, and persons guilty of domestic violence. Immediate destruction of these records can only serve the interests of criminals.

In response to Ashcroft's decision, we are sponsoring a bill to keep the 90-day retention period intact. The Judiciary Committee must also heighten its oversight of the Justice Department to make sure that the attorney general's special-interest agenda on gun issues does not prevail. As the nation's chief law enforcement officer, Ashcroft has a responsibility to vigorously uphold the laws, including laws with which he disagrees. He has no authority to unilaterally repeal America's gun-control laws.