The nation's biggest telecommunications companies, working closely with the White House, have mounted a secretive lobbying campaign to get Congress to quickly approve a measure wiping out all private lawsuits against them for assisting the U.S. intelligence community's warrantless surveillance programs.

The campaign—which involves some of Washington's most prominent lobbying and law firms—has taken on new urgency in recent weeks because of fears that a U.S. appellate court in San Francisco is poised to rule that the lawsuits should be allowed to proceed.

If that happens, the telecom companies say, they may be forced to terminate their cooperation with the U.S. intelligence community—or risk potentially crippling damage awards for allegedly turning over personal information about their customers to the government without a judicial warrant.

"It's not an exaggeration to say the U.S. intelligence community is in a near-panic about this," said one communications industry lawyer familiar with the debate who asked not to be publicly identified because of the sensitivity surrounding the issue.

But critics say the language proposed by the White House—drafted in close cooperation with the industry officials—is so extraordinarily broad that it would provide retroactive immunity for all past telecom actions related to the surveillance program. Its practical effect, they argue, would be to shut down any independent judicial or state inquires into how the companies have assisted the government in eavesdropping on the telephone calls and e-mails of U.S. residents in the aftermath of the September 11 terror attacks.

"It's clear the goal is to kill our case," said Cindy Cohn, legal director of the Electronic Frontier Foundation, a San Francisco-based privacy group that filed the main lawsuit against the telecoms after The New York Times first disclosed, in December 2005, that President Bush had approved a secret program to monitor the phone conversations of U.S. residents without first seeking judicial warrants. The White House subsequently confirmed that it had authorized the National Security Agency to conduct what it called a "terrorist surveillance program" aimed at communications between suspected terrorists overseas and individuals inside the United States. But the administration has also intervened, unsuccessfully so far, to try to block the lawsuit from proceeding and has consistently refused to discuss any details about the extent of the program—rebuffing repeated congressional requests for key legal memos about it.