Minnesota union leader David Foster Wednesday night took to the Democratic National Convention stage to hammer Mitt Romney's Bain Capitol.

"I had to stand in a rented auditorium in front of hundreds of steelworkers in their 50s and 60s, and retirees and widows in their 70s and 80s, and told them Romney and Bain had broken their promises," said Foster. Foster, now executive director of the BlueGreen alliance, led local steelworkers at a plant Bain bought and later closed, after a bankruptcy.

Foster was one of three speakers to bash Bain from the convention stage.

Update Bain Capital sent a statement in reaction to the speakers: "Bain Capital grows companies and improves their operations. It is disappointing to watch the distortion of our record and the political hyperbole that often occurs during campaigns. We are extremely proud of our employees and management teams who have grown over 80 percent of the more than 350 companies in which we have invested over 28 years."

Here is Foster's speech:

David Foster