Marc Elrich is one of six Democrats in the race for Montgomery County executive. (Katherine Frey/The Washington Post)

Marc Elrich, a longtime Democrat on the Montgomery County Council, picked up his latest endorsement in the race for county executive Wednesday from the Metropolitan Washington Council AFL-CIO.

A release from the Elrich campaign said the Metropolitan Washington Council voted unanimously to back Elrich, who faces five other Democratic opponents vying to succeed County Executive Isiah Leggett (D).

The release credited Elrich's support for food and commercial workers in negotiations with grocery stores before his time on the council in the 1990s and his support of nurses trying to unionize at Holy Cross Hospital.

"We will mobilize our members and make the case to voters that he is the best candidate to move Montgomery County forward," said Jackie Jeter, president of the Metropolitan Washington Council AFL-CIO and president of ATU 689, which represents workers at the Washington Metropolitan Area Transit Authority.

Earlier this week, Elrich was endorsed by SEIU Local 32BJ. In December, he was endorsed by CASA in Action.