MADISON, Wis. (AP) — Hundreds of nurses who work for UW Health plan to notify administrators of their intention to strike if they don’t recognize their union in a protracted battle to regain bargaining rights.

The union, SEIU Healthcare Wisconsin, said it will issue the legally required 10-day notice of its intent to strike on Friday, setting the clock ticking for a possible strike from Sept. 13 to Sept. 16, the Journal Sentinel reported.

The notice follows a vote taken by hundreds of nurses last month in which 99% approved moving forward with the strike, according to the union.

The health care system, formally called the University of Wisconsin Hospital and Clinic Authority, includes several clinics in the greater Madison area, as well as UW Health hospital, Madison East Hospital and the American Family Children’s Hospital. It employs 3,400 nurses, with the union estimated to include 2,600 nurses.

The COVID-19 pandemic has contributed to burnout and concerns among nurses over increasingly higher patient-to-staff ratios. Nurses across the country, including those in Minnesota, are threatening to strike if working conditions do not improve.

The vote for union recognition has been brewing since 2011 when the state Legislature passed Act 10 and UW Health was removed from the state’s Labor Peace Act, which required UW Health to recognize employee unions and collectively bargain with them.