WASHINGTON — A measure aimed at giving whistleblower protection to people who report suspicious terrorist-related activity is getting new support from a city Democrat who voted against it earlier this year. Rep. Jerrold Nadler, whose district includes Lower Manhattan parts of Brooklyn, and the Upper West Side, said yesterday that he would vote to support what is known as the “John Doe” amendment if given another chance.

A Republican of Long Island, Rep Peter King, introduced the measure after the lawsuit that the Council on American-Islamic Relations filed on behalf on six imams who were removed from a USAirways flight in November. It would extend immunity provisions under a federal “Good Samaritan” law to those who report suspicious activity.

“We want to encourage people to report what they think is suspicious,” Mr. Nadler said in an interview yesterday. Along with every Democrat on the city’s congressional delegation except Rep. Anthony Weiner, Mr. Nadler voted against the measure when Mr King introduced in as a “motion to recommit” on a rail security bill in March. Those motions are usually voted along party lines, and Mr Nadler said he did not read it.