NEW YORK - Mayor Bill de Blasio's proposed streetcar got a boost from a union that's made him a frequent target.

It's a story first reported by NY1.

Transport Workers Union Local 100 says it supports the Brooklyn-Queens Connector project.

The proposed 16-mile line would connect waterfront neighborhoods in Brooklyn and Queens, from Sunset Park to Astoria.

The unions made clear this is an endorsement of the line, not the mayor's bid for re-election.

"We believe he's doing the right thing with this project. And we intend to support the project. We intend to do everything we can politically to get the project built, wherever we can help out with that matter. And then we intend to organize the project," said TWU Local 100 President John Samuelsen.

"Nobody knows about the importance of public transit and what it means for New Yorkers and how to get around from day to day than TWU members and workers," said Friends of the BQX Executive Director Ya Ting Liu.

The city hopes to break ground on the project in 2019 and launch service by 2024.