New York City Mayor Bill de Blasio on Tuesday endorsed Democratic Senate candidate Dell Smitherman, the primary opponent to Brooklyn Sen. John Sampson — a nod that follows the endorsement from Gov. Andrew Cuomo.

“Dell has been a dedicated organizer and activist for years, and he’s been a steadfast ally in my fight to make life better for working families in New York,” de Blasio said in a statement released by Smitherman’s campaign. “From fighting for a higher minimum wage to expanding healthcare access and public transit, Dell’s priorities are the priorities of working New Yorkers. I’m proud to endorse his campaign for Senate, and look forward to doing my part to ensure he wins on Primary Day.”

Over the weekend, Smitherman was endorsed by Cuomo, who praised the labor advocate for “fight for working and middle class New Yorkers.”

“I am proud to endorse Dell Smitherman for State Senate,” Cuomo said. “Dell is a lifelong Brooklyn resident who has dedicated his career to fighting for working and middle class New Yorkers. He helped rally community support for our successful effort to raise the minimum wage and I look forward to working together in Albany next year to build on that progress and pass the Dream Act and the Women’s Equality Act.”

Both Cuomo and de Blasio have pledged to help Democrats regain full control of the Senate, helping broker a new coalition agreement with the mainline conference and the Independent Democratic Conference.

A Sampson defeat next Tuesday would be an important piece of that puzzle falling into place, considering the lawmaker is technically not part of any legislative conference in the chamber.

Sampson is facing charges of embezzling from an escrow account he managed in order to fund his campaign for district attorney in Brooklyn. The one-time Senate leader was indicted again earlier this year for lying to federal law enforcement.

Smitherman has been endorsed by the Working Families Party as well as a host of key labor groups: AFL-CIO, 1199 SEIU, 32 BJ SEIU, Hotel and Motel Trades Council, Communication Workers of America 1180, Communication Workers of America District 1, UAW, Transport Workers Union, Retail, Wholesale, and Department Store Union, United Food and Commercial Workers.

Smitherman is also the preferred candidate of the good-government organization Citizens Union in the primary race.