The Irish Nurses and Midwives Organisation says Our Lady's Hospital in Navan will be "effectively shut down" if the HSE orders it to stop performing surgery.
Staff are being briefed on the hospital's future.
If surgery is removed, patients will be treated in Dublin and in other hospitals in the area.
Industrial Relations Officers with the INMO, Tony Fitzpatrick, said there are more than 200 nursing jobs on the line.