The Royal College of Nursing (RCN) is to start balloting members on industrial and strike action over staffing and pay in Northern Ireland.
Voting papers are being posted to RCN members working in health and social care services, with the ballot due to last for four weeks.
The RCN’s Northern Ireland director Pat Cullen said there was a pay crisis.
But the Department of Health said the RCN was “making demands it knows the department cannot meet”.
It is the first time in the nursing union’s 103-year-history that its members have been balloted.
Staff will be asked if they are willing to take industrial action, including strike action, over what Pat Cullen said were the “unacceptable