WASHINGTON – The Senate is expected to vote Tuesday on whether to grant retroactive immunity to telecommunications companies that assisted in illegal surveillance of suspected terrorists when it wraps up voting on the updated intelligence surveillance bill, according to the office of Sen. Olympia Snowe, R-Maine.

Snowe, who supports immunity, voted against two amendments to the Foreign Intelligence Surveillance Act, or FISA, that were rejected by the Senate on Thursday. The 1978 act allows the government to conduct electronic and other means of surveillance in national security matters.

The first amendment would have allowed the court established by the intelligence act to prevent the government from using information collected on a U.S. citizen if the procedures for gaining the information were illegal.

Snowe, a member of the Senate Select Committee on Intelligence, opposed the amendment because it would have restricted access to vast amounts of intelligence information, according to a statement from her office.

“Rather than requiring only that procedures be corrected or collection ceased, this amendment would have prevented actual intelligence from being used,” Snowe said. “I was concerned that these inflexible, additional requirements could have a profound effect on our ability to gather intelligence critical to protecting our homeland.”

The second amendment would have blocked the government from conducting surveillance on a foreigner if the true intention were to listen to a U.S. citizen on the other end of the communication.

Snowe said she opposed the amendment because “the underlying bill already explicitly states that a person in the United States cannot be targeted for surveillance without a warrant.”

The White House has received substantial support in the Senate from Snowe and others in its quest to grant immunity to the private companies. The House version of the bill does not grant immunity. After the expected Senate vote on Tuesday, the House and Senate will have little time to settle disagreements over immunity before the current law expires on Saturday.

Some House Democrats have already expressed their support for immunity, including 21 Democrats who sent a letter to House Speaker Nancy Pelosi, D-Calif., on Jan. 28. The congressmen were all members of the Blue Dog Coalition, a group of conservative and moderate Democrats.

Though a member of the Blue Dog Coalition, Rep. Michael Michaud, D-Maine, did not sign the letter and is opposed to immunity. “In the end, if any laws were broken, someone should be held accountable,” Michaud said.

Sen. Patrick Leahy, D-Vt., chairman of the Judiciary Committee, also opposes immunity because of his belief that those who commit illegal acts should not be let off the hook. A trial is the only way there will be a thorough investigation of the administration’s activities, Leahy said.

Leahy supports an amendment proposed by Sens. Arlen Specter, R-Pa., the senior Republican on the Judiciary Committee, and Sheldon Whitehouse, D-R.I., another member of the committee, that would hold the government and not the private companies directly responsible. Michaud said he would consider supporting this amendment.

Snowe said subjecting private companies to lawsuits may endanger the government’s relationship with them in the future and that their cooperation in security and intelligence projects is crucial to the country’s national security.