Mr. Grimm has out-raised some of the city’s most liberal Democrats, including labor friend and profilic fundraiser, Jerry Nadler of Manhattan, who took in $121,500 this election cycle from labor-affiliated PACs.

Labor leaders who support Mr. Grimm said they are doing so for two reasons. He has consistently supported the Davis-Bacon Act, which requires that workers on federally funded projects are paid the “prevailing wage.”

The House often seeks exemptions to the 71-year-old law in spending bills, which are supported by Republicans such as Ms. Hayworth but opposed by Mr. Grimm. Further, Mr. Grimm supports the use of project labor agreements on federal projects, generally ensuring the use of union workers.

“When it comes to Davis-Bacon and project labor agreements, that’s what puts food on our table,” said Jack Kittley, the political director for District Council 9 of the International Union of Painters and Allied Trades. “Mike Grimm is one of a really small handful of majority Congress members that support those issues.”