Anthony Brown kicks off his campaign for Maryland governor in May. (Photo by Astrid Riecken For The Washington Post)

Lt. Gov. Anthony G. Brown (D) is slated to pick up the first endorsement from a labor union in Maryland’s 2014 gubernatorial race.

The Laborers’ International Union of North America Mid-Atlantic Region plans to offer Brown a tour of its Baltimore training center on Thursday and then offer its endorsement. The organization’s members are engaged in building construction, environmental remediation, highway construction and other service work.

“We have no doubt that Anthony Brown is absolutely the best choice to serve as governor, and we wholeheartedly throw our support behind his campaign,” said Dennis L. Martire, the union’s vice president and Mid-Atlantic regional manager.

Brown is likely to face at least two other Democrats in a competitive primary next June: Attorney General Douglas F. Gansler (D) and Del. Heather R. Mizeur (D-Montgomery).

Gansler has yet to formally kick off his campaign. Mizeur launched her bid last month.