Maryland Lt. Gov. Anthony Brown speaks to supporters as he kicks off his campaign for governor in May. (AP Photo/Jose Luis Magana)

Lt. Gov. Anthony G. Brown (D) on Tuesday picked up an endorsement of his 2014 gubernatorial bid from the Maryland chapter of a plumbers and pipefitters union.

The United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada became the second labor organization to back Brown, citing his work on health-care reform, among other issues.

In the June 2014 Democratic primary to succeed Gov. Martin O’Malley (D), Brown faces Attorney General Douglas F. Gansler (D) and Del. Heather R. Mizeur (D-Montgomery).

Brown has moved more aggressively than his rivals to roll out endorsements in the early stages of the race.