The Working Families Party, the influential progressive flank of the Democratic Party, has endorsed Manhattan state Assemblymember Yuh-Line Niou for the highly competitive 10th Congressional District seat representing Lower Manhattan and parts of Brooklyn, according to Ravi Mangla, a spokesperson for the party.

Niou, whose Assembly district covers Lower Manhattan, has already received the backing of several progressive groups, including New York Communities for Change, which is a member of the WFP.

“I am thrilled to have the endorsement of the Working Families Party, which is and has always been my home,” Niou said on Twitter. “I know from experience how big of a coalition we have built and what we have done to drive progressive change. Together, we will build a more just and fair democracy.”

She was among four candidates who sought the WFP’s endorsement. The others were former Mayor Bill de Blasio, Westchester County Rep. Mondaire Jones, and City Councilmember Carlina Rivera.

With 15 Democrats seeking to get on the August 23rd ballot for the 10th Congressional District seat, who the WFP decides to endorse could be a game-changing moment in the race. The party’s backing is seen as a critical seal of approval among left-leaning voters that also can help energize fundraising. The newly carved district folds in several of the city’s most liberal enclaves, including Greenwich Village and Park Slope.

Several members told Gothamist that while Niou was the overwhelming favorite, some in the party tried to make the case that they should stay out of the race altogether to avoid the risk of alienating progressive candidates and their allies.

Founded in Brooklyn, the party has deep roots in the district and has historically wielded sway in brownstone Brooklyn, which makes up a large portion of the newly drawn 10th Congressional District. The party is known for championing working-class issues, including affordable housing as well as the creation of jobs, and policies that address the worsening crisis around climate change.

“This is an area where the WFP-endorsed candidates get a lot of votes,” said John Mollenkopf, the director of the Center for Urban Research at CUNY.

Mollenkopf analyzed the data and found that in the 2020 presidential election, the areas that make up the new district cast the highest share of votes for Biden on the WFP line — 13.5% — compared to any of the other congressional districts in New York. The city-wide average was 7.2%.

Turnout is expected to be low for the August primary, given the unusual timing. Mollenkopf said it would be reasonable to expect around 60,000 votes, although he warned that may be an optimistic estimate.

Other neighborhoods in the district include Greenwich Village, Chinatown, Sunset Park and portions of Borough Park.

Among the high-profile endorsements so far, Brooklyn Rep. Nydia Velázquez last Friday announced that she would back Rivera, a fellow Latina elected official. In doing so, she skipped over her fellow House colleague, Westchester County Rep. Mondaire Jones. After redistricting, he decided not to run for re-election in his suburban district to avoid a contest against Rep. Sean Patrick Maloney, the head of the Democratic Congressional Campaign Committee.

In an interview with Gothamist earlier this month, Sochie Nnaemeka, the director of the New York Working Families Party, said that any candidate they endorsed would need to show that they had a strong campaign apparatus as well as an ability to fundraise.

Citing the short timelines, she said candidates must “be ready to run and win.”