WASHINGTON - The Justice Department on Thursday scrapped a controversial proposal to allow federal law-enforcement agencies to lie about the existence of government documents being sought by the public.

The decision was cheered by the American Civil Liberties Union, other open-government groups and a bipartisan group of U.S. senators who had urged the agency to withdraw the proposed rule.

"Government accountability can only be assured through transparency," said Laura W. Murphy, director of the ACLU's Washington legislative office. "Putting an end to lies about the mere existence of documents is one step toward restoring Americans' trust in their government."

The proposed regulation would have applied to certain documents that members of the public may request under the Freedom of Information Act, known as FOIA. Some sensitive records, including information about FBI informants, are already excluded from the requirements of the act because revealing them could tip off criminals or threaten public safety.

However, instead of just denying a request, the proposed rule would have allowed Justice Department officials to "respond to the request as if the excluded records did not exist," even when they do.

Open-government groups said such a response would have amounted to lying to the public.

Assistant Attorney General Ronald Weich, in a letter Thursday to Sen. Charles Grassley, R-Iowa, said he disagreed with that characterization but was withdrawing the controversial rule because the Obama administration believes in government transparency.

The proposed rule would have codified a little-known Justice Department practice of false denials that began in 1987 during the Reagan administration. Then-Attorney General Edwin Meese told agency officials to deny the existence of certain sensitive law-enforcement documents when members of the public requested them.

"While the approach has never involved 'lying,' as some have suggested, the Department believes that past practice could be made more transparent," Weich wrote to Grassley. The Iowa senator is the senior Republican on the Senate Judiciary Committee, which oversees the Justice Department.

Sen. Patrick Leahy, D-Vt., chairman of the Judiciary Committee and a longtime champion of the Freedom of Information Act, said the Justice Department made the right decision by withdrawing the controversial rule.

"For five decades, the Freedom of Information Act has given life to the American value that in an open society, it is essential to carefully balance the public's right to know and government's need to keep some information secret," Leahy said in a written statement. "The Justice Department's decision to withdraw this proposal acknowledges and honors that careful balance and will help ensure that the American people have confidence in the process for seeking information from their government."

The ACLU and the senators said they will collaborate with the Justice Department as it seeks to update its overall FOIA regulations.

"We will work with the Justice Department to develop a truthful and informative response to all FOIA requesters, even where the government is authorized to withhold documents from release," said Murphy of the ACLU.

In a letter to the Justice Department last month, the ACLU, along with Citizens for Responsibility and Ethics in Washington and OpenThe Government.org, offered a suggestion for how government officials can respond without lying.

"The agency should simply respond that, 'We interpret all or part of your request as a request for records, which, if they exist, would not be subject to the disclosure requirements of FOIA . . . and we therefore will not process that portion of your request,' " they wrote.