SEIU Wisconsin has filed new unfair labor practice charges with the National Labor Relations Board against St. Mary’s Hospital in Madison and Dean Medical Group, escalating a labor dispute involving nearly 1,200 nurses who voted to unionize this year. The union alleges that St. Mary’s fired a nurse in August because of support for the union. Its charges against Dean, which operates 10 outpatient clinics in Dane County, allege that managers restricted union materials and insignia, surveilled employees, held meetings that employees were pressured to attend, and threatened discipline, termination or negative workplace changes tied to union activity or the vote. The allegations have not been proven. SSM Health, which includes both providers, denied violating federal labor law. In a statement, the St. Louis-based Catholic nonprofit said there had been “no unlawful conduct” and that it respects and values its employees. Nurses at Dean clinics voted 71% in favor of union representation in September, following an 89% vote by St. Mary’s nurses in June. SSM has declined to bargain with the St. Mary’s nurses’ union, citing challenges to the June election. The union filed an earlier charge alleging that the hospital violated federal law by refusing to bargain. The latest filings add to previous NLRB charges, including a September allegation that Dean fired a nurse and several complaints against St. Mary’s. Dean nurse Michelle Camilleri said nurses sought union representation to have a voice in workplace decisions and improve patient care. She said policies and practices had made it difficult for nurses to provide the standard of care they wanted, and had contributed to some nurses leaving SSM. “We would like to see SSM come to the table,” Camilleri said. The labor dispute involves nurses across a major Madison hospital and a network of county clinics, with both sides’ positions now before the federal labor board.