Rep. Jerrold Nadler got a $100 million boost yesterday that keeps alive a contentious multibillion-dollar transportation project he’s been championing for decades, but some in New York have already come out against it.

Mayor Bloomberg has said the proposed project – a freight tunnel that would connect New Jersey to Brooklyn – “would destroy neighborhoods.”

The grant, which is part of a federal compromise transportation bill, would be the largest Mr. Nadler has secured for consideration of the tunnel construction, which the congressman says could eliminate up to a million truck trips across the Hudson River crossings a year.

Yet while the Cross Harbor Freight Rail Tunnel has a long list of elected proponents, it hinges on the use of an existing rail line in Brooklyn to transport goods across the borough and into Queens once they arrive from New Jersey. Residents who live along the line are enraged by the idea of trains roaring through their backyards, and in some parts of the city, opposition has been fierce.

A spokesman for Mr. Bloomberg, Edward Skyler, said by e-mail yesterday that there were more pressing transportation needs in the city and that “the mayor doesn’t think the project makes sense.”

In March, Mr. Bloomberg, a Republican who needs conservative votes to win reelection, reversed his 2003 position on the tunnel. He told an audience in a politically key area of Queens that would be home to a truck-loading hub at the end of the train line that he was against it.

Council Member Simcha Felder, who represents parts of Brooklyn, said yesterday he was glad Mr. Nadler did not secure the $700 million the congressman was lobbying for, but he still called the allocation a “waste of taxpayers’ money.”

“Congressman Nadler has had this fantasy for some 20-odd years,” Mr. Felder said. “It’s about time that he gave up the fantasy. It’s a waste of taxpayers’ money.”

Mr. Nadler dismissed that characterization. He said the allocation was “fantastically significant” and that it was the second largest funding allotment under the “mega project” umbrella in the bill, second only to a project House Speaker Dennis Hastert was pushing in his Illinois district. He said the $700 million was an initial estimate, but he hadn’t expected that amount to come through.

“I’m elated,” he said. “It gives us the funding we need to do all of the design and engineering work which takes us to the next bill in 2009.”

The tunnel is expected to cost between $4.8 billion and $7.4 billion, depending on whether a single or double rail is built. Mr. Nadler, who represents parts of Manhattan and Brooklyn, said it is desperately needed because the city streets, already clogged with trucks, are not going to be able to keep up with economic growth.

In the past, he has acknowledged that there would be more trucks picking up goods at loading points in Queens and Brooklyn, but he said overall the project would ease congestion citywide, reduce pollution, and act as a backup route for freight in the event of a catastrophe. He also said all four Democrats running for mayor, as well as roughly 140 politicians statewide, support it.