Former city Managing Director Kirk Caldwell has picked up two more endorsements in his campaign for Honolulu mayor.

Hawaii Laborers’ Union Local 368 and the Operating Engineers Local Union 3 on Tuesday announced their endorsement of Caldwell over incumbent Mayor Peter Carlisle and former Gov. Ben Cayetano.

The Laborers’ Union represents about 5,000 Hawaii workers in construction industry including landscaping and environmental remediation, while the Operating Engineers Union has about 3,000 members working as heavy equipment operators and construction workers, but also public employees, such as maintenance workers.

“We know that Kirk Caldwell will serve our industry and communities well,” Pane Meatoga, district representative for the Operating Engineers, said in a news release. “His legislative and executive experience have made him the candidate of choice. “

Caldwell has received all of the union endorsements so far in the race, including those of the Hawaii Government Employees Association, the United Public Workers, the State of Hawaii Organization of Police Officers, the Hawaii Fire Fighters Association and various other smaller unions.