"It is with great pride and excitement that we endorse two outstanding leaders who are great friends of our union and staunch advocates for working families," the union's president, George Gresham, said in a public statement. "1199 members are proud to stand with Bill and John and we look forward to doing everything in our power to get them both elected."

1199 SEIU is one of the major partners of the Working Families Party, a labor-backed organization which has already endorsed both de Blasio and Liu (after some donations to the party were made).

During the Working Families Party vote for mayor, 1199 SEIU voted to back Bill Thompson over Michael Bloomberg.