House and Senate conferees reached a tentative deal Tuesday in negotiations on Sept. 11 legislation that likely will clear the way for passage of the bill this week.

Conferees for the bill (HR 1) had haggled over a so-called “John Doe” provision, which Republicans favored but some Democrats sought to modify.

A Republican aide to the House Homeland Security Committee said compromise language on the measure would give civil immunity to “good-faith” informants of terrorist activity, using the definition of such activity contained in a House bill (HR 2291) introduced May 14.

New York Rep. Peter T. King, ranking Republican on the House Homeland Security Committee, was among the leaders of the push for the measure, which is a response to an incident at an airport in Minneapolis last fall in which six Muslim men were thrown off an airplane because of passenger complaints of suspicious behavior. The men have filed a lawsuit against those who complained.

“In a post-9/11 world, vigilance is essential to security,” King said in a statement praising the final language on civil immunity. “I’m proud to announce that common sense has prevailed and heroic Americans who report suspicious activity will be protected from frivolous lawsuits,”

King had said that Bennie Thompson, D-Miss., House Homeland Security Committee chairman, wanted to apply the provision only to federal claims, excluding claims in state and local courts. Republican aides said that the compromise language would apply to local, state and federal courts.

The liability shield would be retroactive to November 2006, which is when the incident in Minneapolis occurred.

A spokesman for King said the lawmaker would sign the conference report and planned to vote in favor of final passage of the legislation. The bill would implement several recommendations of the independent, bipartisan Sept. 11 commission.

Republicans, as well as Joseph I. Lieberman, I-Conn., Senate Homeland Security and Governmental Affairs Committee chairman, pushed for the liability shield even though it was not included in either the House or the Senate version of the Sept. 11 bill. However, the provision was included in a transit security bill (HR 1401) the House passed March 27.

Despite King’s decision to back the bill in its current form, the Sept. 11 bill will not go the president without some GOP opposition. Florida Rep. John L. Mica, ranking Republican on the House Transportation and Infrastructure Committee, sent a letter July 24 to conferees urging them not to sign the conference report, citing concerns about a provision that would mandate the scanning of all cargo containers entering the U.S. seaports within five years and a provision on the distribution of transit grants.

Maine Sen. Susan Collins, ranking Republican on the Homeland Security and Governmental Affairs Committee, has said that she will not sign the conference report because of the cargo screening provision.