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

Maryland Lt. Gov. Anthony G. Brown’s gubernatorial campaign picked up the endorsement Saturday of the Maryland-D.C. AFL-CIO Council, adding to a list of high-profile supporters in next year’s Democratic primary.

The group serves as the umbrella organization for labor in the state, claiming close to 300,000 members, and it has traditionally provided substantial on-the-ground resources for candidates it supports.

Fred Mason, president of the Maryland-D.C. AFL-CIO, cited Brown’s work as lieutenant governor on school funding and workforce issues, as well as his commitment to push for raising the minimum wage in Maryland.

Brown (D) faces Attorney General Douglas F. Gansler (D) and Del. Heather R. Mizeur (D-Montgomery) in the June Democratic primary. Both Democrats have also pledged to make raising the minimum wage a priority.

In a statement, Mason said the union was “fired up” to support Brown and his running mate, Howard County Executive Ken Ulman (D).

“With nearly 300,000 Maryland brothers and sisters in the AFL-CIO, Anthony Brown and Ken Ulman can count on us to work hard to help them win on Election Day,” Mason said.

Gansler has sought to play down a growing list of endorsements that have broken Brown’s way, including one a week ago by the Maryland State Education Association, the state’s largest teachers lobby.

The endorsements, Gansler has argued, show that Brown is the favorite of the “Democratic establishment,” while he is more concerned with representing everyday voters.

Besides the labor and teachers groups, Brown’s backers include several prominent Maryland Democrats. He has the support of Gov. Martin O’Malley (D), whom he is seeking to succeed, as well as Sen. Barbara A. Mikulski (D-Md.), House Minority Whip Steny H. Hoyer (D-Md.), state Senate President Thomas V. Mike Miller Jr. (D-Calvert) and House Speaker Michael E. Busch (D-Anne Arundel).