Labor Department filings show Mercedes-Benz contracted with three consulting firms to help win this month’s union election at its Vance auto plant.

The consultants brought in at least 11 people for anti-union meetings with employees ahead of the election, according to the Huffington Post.

Workers this month at Vance and the company’s Bibb County electric battery plant voted 2,045 to 2,642 against UAW representation — a margin of 597 votes.

Last week, the United Auto Workers petitioned the National Labor Relations Board to reject the results and order a new election.

According to forms with the Labor Department’s Office of Labor Management Standards, the company hired firms from California, Oklahoma and Florida. The consultants were hired to speak to production and maintenance employees, factory technicians and “all facility team members.”

The forms do not disclose how much the company spent on the firms.

The consultants were likely hired for what are known as “captive audience” meetings, where employees are required to attend to hear anti-union messaging. Consultants can earn around $3,200 a day, according to the report.

The meetings were one of six points raised by the union during an unfair labor practices filing against Mercedes. Union organizers also raised captive audience meetings in challenges to elections at Amazon in Bessemer.