Sen. Al Franken (D-Minn.), left, confers with an aide during a hearing on Capitol Hill on July 23. (J. Scott Applewhite/AP)

Sen. Al Franken (D-Minn.) lashed out this morning at "the lack of transparency" surrounding the collection of Americans' phone records. Speaking at a Senate Judiciary Committee hearing, Franken blasted top intelligence officials for delays in declassifying secret government documents authorizing the program.

"I don't want transparency only when it's convenient to the government," Franken said. The Office of the Director of National Intelligence, he added, "has known for weeks that this hearing was coming and ODNI released this only in the minutes before this hearing began. That doesn't engender trust."

Franken vowed to introduce new legislation that would force the Obama administration to reveal more about the NSA's controversial bulk surveillance programs.

The documents in question include two reports to Congress, one from 2009 and another from 2011, defending the program to lawmakers. They also include a copy of the court order from the Foreign Intelligence Surveillance Court granting law enforcement the permission to collect U.S. phone records.

Sen. Sheldon Whitehouse (D-R.I.) charged that the administration's response to the NSA leak revelations has been slow from the beginning, reflecting a culture of secrecy that grants the executive branch an inherent advantage over the checks of the legislative branch.

"It all came out in response to the leaker," said Whitehouse, in an overlapping exchange with Deputy Attorney General James Cole. "When this thing burst ... the rumor was all the way across town before you could get your boots on."

Other senators, including Mike Lee (R-Utah), Dick Durbin (D-Ill.)  and Patrick Leahy (D-Vt.) also expressed concern about excessive secrecy at the NSA.

Until now, much of the debate surrounding the NSA programs has involved questions about the proper balance between security and privacy. But today's hearing marked one of the few times that lawmakers have invoked the proper balance between classification and declassification. Whitehouse accused the government of using classification as a convenient way to gain a political edge.

"I think it's done because it gives the executive branch an advantage over the legislative branch," Whitehouse said. "We need to balance the value of declassification against the value of classification. You guys are way too one-sided."