WASHINGTON  Democratic senators who have been working on legislation providing greater protections to reporters who refuse to identify confidential sources are backpedaling from WikiLeaks, the Web site that recently disclosed more than 75,000 classified documents related to the Afghanistan war.

Senators Charles E. Schumer and Dianne Feinstein, Democrats of New York and California, are drafting an amendment to make clear that the bill’s protections extend only to traditional news-gathering activities and not to Web sites that serve as a conduit for the mass dissemination of secret documents. The so-called “media shield” bill is awaiting a vote on the Senate floor.

“WikiLeaks should not be spared in any way from the fullest prosecution possible under the law,” Mr. Schumer said in a statement. “Our bill already includes safeguards when a leak impacts national security, and it would never grant protection to a Web site like this one, but we will take this extra step to remove even a scintilla of doubt.”

The bill would allow reporters, when faced with subpoenas seeking to compel them to testify about their confidential sources, to ask a federal judge to quash the demand rather than fining or jailing them for contempt of court if they refuse to comply. About three dozen states have such a law for state courts.