Voice of America programs — more than 70 for television and 200 for radio — are broadcast in 45 languages, and it has affiliates around the world.

The issue has been building for some time, and the changes included in the bill are supported by some prominent journalists like Walter Isaacson, a former chairman of CNN and editor of Time magazine who once led the Broadcasting Board of Governors.

Hillary Rodham Clinton, the former secretary of state, has said the board — which has jurisdiction over the V.O.A. and the other government-financed agencies — was dysfunctional. A recent audit found numerous problems with the board’s use of contractors along with $3.5 million in questionable costs. The agency’s budget is about $200 million annually.

The House bill would turn the board into an advisory body and create a position for a full-time chief executive to run the agency day to day.

Dozens of journalists at the news agency said that the legislation represented a threat to its existence, and that they were angry union leaders issued the endorsement without consulting members.

“I didn’t see anything that went out to members telling us that they were doing this,” said one union member who asked not to be quoted by name in criticizing the legislation because she did not have permission to speak on the record. “It gives the impression that we as journalists support this bill, and we do not.” She said she did not find out about the union’s support until the Foreign Affairs Committee posted the letter of support on its website.

Mr. Shamble denied that account. He said the decision to support the bill was made by the union’s executive committee after consulting members. The union also presented its positions at meetings, he said.