Telecommunications companies that helped the government eavesdrop on domestic phone and computer lines between 2001 and 2007 without court orders can escape civil lawsuits if the government certifies they acted with the president's authorization, under a draft Senate bill.

But Sen. Chris Dodd, a Democratic presidential candidate, has said he will put a "hold" on the legislation, effectively preventing it from getting to a floor vote.

The legislation, being debated Thursday in the Senate Intelligence Committee, would remove a major obstacle to a new government eavesdropping bill which the White House has vowed to veto unless it immunizes telecom companies from lawsuits.

But approval by the intelligence panel doesn't guarantee smooth sailing for the legislation, even without Dodd's hold. It still must get the blessing of the Senate Judiciary Committee, whose top Republican and Democratic members have expressed skepticism about the immunity provision. And the bill remains stalled in the House, where it ran aground Wednesday in a partisan dispute over the immunity issue and the broader question of how much oversight power the courts should have over surveillance.

The bill was crafted in a compromise with the White House after some members of the intelligence panel and senior staff were allowed to read classified documents the administration provided relating to warrantless wiretapping. The documents have not been shared with the Judiciary Committee, which subpoeaed them in June.

The draft bill would direct civil courts to dismiss lawsuits against telecommunications companies if the attorney general certifies that the company rendered assistance between Sept. 11, 2001 and Jan. 17, 2007, in response to a written request authorized by the president, to help detect or prevent an attack on the United States.

Suits also would be dismissed if the attorney general certifies that a company named in the case provided no assistance to the government. The public record would not reflect which certification was given to the court, according to Democratic and Republican aides who spoke on condition of anonymity because the committee had not yet acted.

Committee member Sen. Russell Feingold, D-Wis., said he would not support any immunity provision because the documents the panel reviewed proved to him the wiretapping activities were illegal.

"The documents made available by the White House for the first time this week only further demonstrate that the program was illegal and that there is no basis for granting retroactive immunity to those who allegedly cooperated," Feingold said in a statement.

Dodd, who was not in Washington on Thursday, said he pledged to voters to do everything he could to stop the bill from becoming law, and called the legislation "amnesty for telecommunications companies that enabled the president's assault on the Constitution by providing personal information on their customers without judicial authorization."

The bill, which would expire in six years, also would enshrine in law an executive order that requires the attorney general to certify there is probable cause to believe an American is an agent of a foreign power before the government can begin surveillance. It would amend the 1978 Foreign Intelligence Surveillance Act, the law that sets out how the government may legally conduct electronic surveillance.