The United Public Workers union announced it is endorsing businessman Keith Amemiya for Honolulu mayor while the Operating Engineers Local 3 threw its support behind former Congresswoman Colleen Hanabusa.

Those are the two latest endorsements in a rapidly heating up mayor’s race. The primary election is Aug. 8 but in this year’s, first-ever all-mail voting system, Hawaii voters will receive their ballots on or about July 21.

UPW represents most of the City and County of Honolulu’s blue-collar workers and is the second-largest government workers union in the state. Overall, the organization has approximately 13,500 members, about 7,200 of them on Oahu.

Liz Ho, UPW administrator, said the membership makes up a good number of the essential workers and first-responders on the front line of the coronavirus pandemic.

“We need to elect progressive, union-friendly candidates who will stand up for working people,” Ho said Friday. Amemiya provides those qualities, she said. “More than ever, we need to elect a mayor with the energy and commitment to all workers.”

Amemiya, making his first foray into elective politics, also has the endorsement of the 41,000-member Hawaii Government Employees Association, the state’s largest government workers union. He has also been endorsed by the Plumber and Fitters Local 675.

Meanwhile, Hanabusa this past week scored the endorsement of the 3,500-member Operating Engineers Local 3 union.

Union district representative Pane Meatoga Jr. said Hanabusa’s campaigns have historically received the organization’s support.

Meatoga pointed out that Hanabusa has served both in Congress and the state Legislature.

“Her knowledge of state and federal branches is essential to what will be needed at City Hall right now and going forward,” he said. “That’s one of the reasons we are standing with her again this year.”

Hanabusa’s other endorsements include the Hawaii State Teachers Association, the International Longshore and Warehouse Union Local 142 and the Laborers’ International Union of North America Local 368.

Among other major endorsements: the State of Hawaii Organization of Police Officers endorsed Rick Blangiardi; and the Hawaii Teamsters and Allied Workers Local 996, the International Association of Bridge, Structural and Ornamental Iron Workers Union Local 625, the Operative Plasterers’ & Cement Masons’ International Association Local 630 and the International Union of Bricklayers and Allied Craftworkers Local 1 endorsed Mufi Hannemann.