A bond is growing between the fledging medical marijuana industry and labor unions, Reuters reports. The United Food and Commercial Workers (UFCW) union, the nation’s largest retail union, has played an increasingly important role in campaigns to allow medical marijuana, according to the article.

UFCW members also helped get-out-the-vote efforts in Colorado in November, when voters in the state approved a recreational marijuana measure.

Union members staff three medical marijuana dispensaries in Los Angeles, and an additional 49 in the city plan to enter into labor agreements with the UFCW, the union says. Officials say the marijuana industry could create hundreds of thousands of members, at a time when overall membership in unions is declining.

Currently, only 3,000 of the union’s 1.3 million members work in the marijuana industry. “Since Election Day, we’ve had a rush to join the union” in states where marijuana is sold legally, said Dan Rush, who leads the UFCW’s cannabis division. He noted if the industry continues to grow, it could add jobs including growers, truck drivers, carpenters and retail clerks.

Some marijuana retailers have invited union members into their shops because they think the union adds legitimacy to their business. Others are concerned hiring union workers could drive up their employment costs.