The White House will allow leaders of the Senate Judiciary Committee to access documents on the Bush administration’s secret spying program, in an effort to win their support for retroactive legal protections covering the telecommunications firms that participated in the program, Democrats said Thursday.

A White House official told Leahy in a phone call Thursday morning that he and Specter could access the confidential documents that outline the involvement of the telecom firms. But according to an aide, the details on how the documents could be accessed have not been worked out. There also is no sign yet that the rest of the Judiciary Committee or Senate leadership may access the documents.

Telephone companies are facing about 40 lawsuits for providing private information to the government, and the Bush administration is trying to wipe away those suits by arguing that the companies acted in the interest of national security. But critics of the language say that if telephone companies and the Bush administration did nothing illegal, then they should not be absolved from litigation. For over a year, Democrats have clamored for the documents explaining why immunity would be needed, only to meet resistance from the White House.

“It’s my understanding that there has been a breakthrough,” Senate Majority Leader Harry Reid (D-Nev.) said. “But again, the Judiciary Committee is going to have to work this out on their own.”

The White House concession didn’t appear to appease key Democrats on the Judiciary Committee.

Panel member Dick Durbin (D-Ill.), the majority whip, said he will need to see the documents before he casts his vote.

“I would like to know what happened before I absolve anyone from liability from the law,” Durbin said. “Naturally, I can’t cast an informed vote on FISA until I know the circumstances.”

Erica Chabot, a spokeswoman for Democrats on the panel, said, “It’s important that all members of the committee have access too.”