Sen. Joe Manchin (D-W.Va.) announced his opposition to Julie Su, President Joe Biden s choice to lead the Department of Labor, likely dooming her chances of confirmation in the narrowly divided Senate.

I believe the person leading the U.S. Department of Labor should have the experience to collaboratively lead both labor and industry to forge compromises acceptable to both parties, Manchin said in a statement. While her credentials and qualifications are impressive, I have genuine concerns that Julie Sus more progressive background prevents her from doing this and for that reason I cannot support her nomination to serve as Secretary of Labor.

Manchin holds outsize leverage over Sus confirmation given unanimous GOP opposition and several undecided senators who caucus with the Democrats , including Jon Tester (D-Mont.) and Kyrsten Sinema (I-Ariz.).

A spokesperson for Sinema told HuffPost the senator doesnt preview her votes and wouldnt comment on her position, but the White House suggested that Sinema also opposed Sus nomination.

The Presidents support for Acting Secretary Su is unwavering, and we hope Senator Manchin and Senator Sinema reconsider their position, a White House official said in a statement on Thursday .

Su, the acting Labor Department secretary, previously served as Californias top labor official, overseeing workplace safety and policing wage theft in the countrys most populous state. Labor unions and progressive groups enthusiastically backed her nomination, saying she would aggressively enforce workplace protections, particularly for the most vulnerable low-wage workers.