INDIANAPOLIS (AP) — Efforts to unionize more than 3,900 nurses at three Indiana University Health hospitals have stalled.

The United Steelworkers union is working to earn support from nurses at IU Health’s Methodist, University and Riley hospitals in Indianapolis. But union officials tell the Indiana Business Journal that there’s no estimated date for a vote.

Nurses interested in unionizing have complained about low staffing levels, low pay and attendance policies.

IU Health spokeswoman Lauren Cislak says the hospital system “believes that union is not in the best interest of our nurses or patients.”

The signatures of the nurses that have already indicated they’d like to unionize are good for one year.

State officials say no hospitals in Indiana have unionized nurses except the federally run Veterans Affairs Medical Center.