A major labor union says it's launching a six-figure ad buy against Gwen Graham, targeting the Democratic front-runner for governor over her family's involvement in the American Dream Miami mega-mall.

UNITE HERE, which represents more than 260,000 mostly service industry workers across the country, says it's going after Graham because of her failure to take a stance on the project, of which her family's company is involved.

"We think that Gwen Graham can't hide behind the fact that it's her family who's involved in the project," said Wendi Walsh, Secretary-Treasurer for UNITE HERE Local 355. "She skirts the issue at every turn."

The union has endorsed one of Graham's opponents, former Miami Beach Mayor Philip Levine, in the governor's race.

The union says it's spending six figures to target more than 800,000 Democratic voters, mostly in South Florida. In addition to advertising on social media and websites, they're buying 50 30-second ad spots during morning and evening shows on CNN, MSNBC, OWN and BET in the Miami/Fort Lauderdale area.

"While Graham and her family make millions," one of the TV ads says, "Florida will be stuck with poverty-wage jobs, endangered wildlife and massive traffic congestion."

The campaign is expected to start today and run through Tuesday.

Walsh says the union has tried to get Graham to come out against the project, to no avail. Graham has repeatedly declined to take a stance on it.

Her campaign's spokesman has said Graham "believes local communities should have the first and final voice on the project and to date, they have strongly supported it."

The union isn't the first to go after Graham about the project. Fellow candidate and Palm Beach billionaire Jeff Greene has already aired television ads attacking Graham. Levine has said he's been against the project from the beginning, but has so far stayed out of the fight.

The mall project, which would feature a theme park and an indoor ski slope, would be America's largest, and it has been strongly opposed by environmental groups over fears that it would encourage more development on the eastern edge of the Everglades.

Despite rhetoric by Graham's opponents, however, the mall is not in the Everglades, and Graham's campaign maintains that she's never had any involvement in its formation.

The mall is being built by Triple Five, the company that developed Minnesota's Mall of America, but part of the 175-acre property is owned by the Graham Companies. The Graham Companies is also planning to build a massive mixed-used development on 300 acres south of the mall.

Graham, like many members of her family, has a small stake in the family company that is worth millions. But she resigned as a member of the board in 2015, when she was elected to Congress, and her campaign says she owns less that 1 percent of voting stock in the Graham Companies.