Iowa’s largest manufacturing employer is facing a potential strike.

Unionized John Deere workers voted Sunday night to reject the company’s latest contract offer. The unions say 90% of members voted against the six-year offer which was for more than 10,000 workers at 14 Deere factories, including those in Davenport, Des Moines, Dubuque, Ottumwa, and Waterloo.

A news release from the Quad Cities-based Deere says the offer “would have made the best wages and most comprehensive benefits significantly better for our employees.” The deadline to reach a new accord and avoid a strike is midnight Wednesday.