WASHINGTON - The Obama administration plans to release a previously secret court order that set out the rules and rationale for the bulk collection of U.S. phone records as officials seek to quell growing unrest in Congress over the government's massive information dragnet.

According to a senior U.S. official, the government has declassified the order by the Foreign Intelligence Surveillance Court that authorized the collection program, which began in 2007. Before that, the National Security Agency had been collecting the records without a court order since after the terrorist attacks of Sept. 11, 2001.

The now-declassified order is expected to be made public Wednesday, when Deputy Attorney General James Cole, NSA Deputy Director John Inglis and other officials are slated to appear before the Senate Judiciary Committee.

Former NSA contractor Edward Snowden disclosed the program in June to the Guardian newspaper and the Washington Post via a secondary order from the court directed at Verizon. The primary order has more details, the official said, including the rules about when the database of phone records may be queried.

Source of internal debate

Since Snowden's disclosures, administration officials have debated about how much information about the program and the court's orders should be released to the public. National security officials have resisted many proposals to declassify information on the program, arguing that virtually any information could potentially be used by terrorist groups to evade U.S. surveillance. Other officials have argued that Congress could kill the program if the administration fails to reassure the public about how the information is gathered and what protections are in place for privacy.

In addition to the court order from 2007, administration officials are also planning to release two white papers on the telephone-data program that were provided to Congress in 2009 and 2011 before the House and Senate voted to reauthorize the law behind it, the senior official said, speaking on the condition of anonymity because he was not authorized to be quoted.

Pointing to Congress

The white papers summarized the program, made clear that it included "bulk collection" and instructed the intelligence committees to provide the papers in a classified setting to all members of Congress, the official said.

The release of those papers is intended to make clear that Congress had the opportunity to be fully informed, despite protests in recent weeks from some members who said they didn't understand the extent of the records collection.