The U.S. Senate defeated on Tuesday an amendment that would take away legal immunity from telecommunications providers that helped the U.S. National Security Agency conduct surveillance on U.S. residents, earning criticism from two civil liberties groups.

The Senate, by a 31-67 vote, defeated an amendment to the FISA Amendments Act, a bill that would make changes to the Foreign Intelligence Surveillance Act of 1978 and allow the NSA program to continue. In the past, the NSA has conducted telephone and e-mail surveillance of U.S. citizens conversing with terrorist suspects overseas without court-approved warrants.

The Senate was scheduled to vote on the full FISA bill late Tuesday.

The Electronic Frontier Foundation (EFF) and the Center for Democracy and Technology (CDT) slammed the Senate vote. "Immunity for telecom giants that secretly assisted in the NSA's warrantless surveillance undermines the rule of law and the privacy of every American," said EFF senior staff attorney Kevin Bankston. "Congress should let the courts do their job instead of helping the administration and the phone companies avoid accountability for a half decade of illegal domestic spying."

It doesn't make sense for Congress to work hard on the FISA bill when the NSA and telecom providers can circumvent the law, added Greg Nojeim, CDT's senior counsel. "The telecom immunity provision sends a message that it's OK for a telecom to assist with unlawful surveillance when secretly asked to do so by the government," he said.

Democratic Senators Chris Dodd of Connecticut and Russ Feingold of Wisconsin had sponsored the amendment to get rid of legal immunity for the telecom providers. AT&T and other telecom carriers are being sued in U.S. court in San Francisco for their participation in the surveillance program, which many civil liberties groups say is illegal.

Last month, U.S. Vice President Dick Cheney said in a speech that it is "entirely appropriate" for U.S. intelligence agencies to seek help from private companies such as telecom providers because agencies don't have all the resources they need to keep the United States safe from terrorism.

"Some providers are facing dozens of lawsuits right now," Cheney said then. "Why? Because they are believed to have aided the U.S. government in the effort to intercept international communications of al Qaeda-related individuals."

A House bill, passed in November, does not include legal immunity for telecom providers that participated in the NSA program. The House and Senate would have negotiate the differences in the two bills before sending the legislation to U.S. President George Bush to sign. Bush has threatened to veto a surveillance bill that does not include legal immunity for telecom providers, but congressional authorization for the surveillance program expires Feb. 15.

It would be counterproductive for Bush to veto a bill that extends surveillance programs that he says are critical, Bankston said. "The only way they can [get legal immunity] is by fallaciously tying it to something critical," he said.

The EFF will push hard to have House negotiators keep the telecom immunity provisions out of the bill that goes to Bush, Bankston added.

The EFF and CDT both prefer the House FISA bill, called the Restore Act. Unlike the Senate bill, the House bill would require court approval of surveillance, and the House version would expire in two years, as opposed to six years in the Senate version. The CDT has produced a chart comparing the two bills.