Adams will officially unveil the endorsement during a press conference with Rivera in downtown Manhattan on Wednesday morning, said the source, who spoke on condition of anonymity.
New Yorkers are headed to the polls for the second primary this year to vote on state Senate and congressional races. Two closely watched Democratic races are in the 10th Congressional District and the 12th Congressional District.
There’s no incumbent in the newly created 10th Congressional District spanning lower Manhattan and parts of Brooklyn, and at least six candidates are considered legitimate contenders.