The Labor Department has changed its interpretation of a new corporate whistle-blower law, a move that will afford workers who report wrongdoing to Congress greater protection against retaliation, two senators said yesterday.

In a letter Friday to Sens. Charles E. Grassley (R-Iowa) and Patrick J. Leahy (D-Vt.), Acting Solicitor Howard M. Radzely reversed the department's contention that only whistle-blower contacts with a "duly authorized" investigative committee of Congress were protected, not those with just any lawmaker. That initial department reading of the Sarbanes-Oxley Act, a corporate accountability law enacted last summer, conflicted with what the two senators said they intended when they wrote the whistle-blower protections into the bill.

"It is the department's view that . . . complaints to individual members of Congress are protected, even if such member is not conducting an ongoing committee investigation," Radzely wrote.

Grassley said the reversal would "make it easier for corporate whistle-blowers to be protected when they speak out on wrongdoing in the boardroom."

"It's a big victory," said Blythe McCormack, a spokeswoman for Leahy.

Grassley and Leahy have sent several letters to White House officials seeking assurances that the Bush administration understood the intent of the law. In September, then-Labor Department solicitor Eugene Scalia filed a friend-of-the-court brief with an administrative review board seeking to overturn a $200,000 punitive damages award won by Assistant U.S. Attorney Gregory C. Sasse of Ohio in a whistle-blower case against the Justice Department.

Scalia, who resigned his post this month to return to private practice, had argued that Sasse did not enjoy whistle-blower protection in his contacts with Rep. Dennis J. Kucinich (D-Ohio), who was looking into reports of toxic materials on federally owned land near the Cleveland airport. Only contacts with investigative panel members are protected, Scalia wrote.

Scalia also argued that a federal prosecutor could not sue the Justice Department over workplace disagreements involving priorities in government litigation.

Sasse, who still has his job, said his supervisors downgraded his performance reviews, did not grant him training opportunities and removed him from some cases in retaliation for his contacts with Kucinich. An administrative law judge ruled that the Justice Department had retaliated against Sasse and found that his contacts with Kucinich were protected.

The Justice Department appealed to the administrative review board, which has not yet ruled on the case.

Whistle-blower advocates said Scalia was attempting to use the case, which concerns whistle-blower provisions in environmental protection laws, to establish a precedent that would undermine whistle-blowers in cases against corporations.

Jeff Ruch, executive director of Public Employees for Environmental Responsibility, a group that defends federal workers on environmental issues, said a central question of the Sasse case -- whether federal prosecutors can be whistle-blowers -- remains unresolved.

A Labor Department spokeswoman declined to comment on the case because it is in litigation.

Steven Bell, Sasse's attorney, said the department's reversal helps his client. "The Labor Department is acknowledging that the substance of the brief it filed is legally inaccurate," he said.