Northern Ireland's health service could be facing a staffing crisis after Unison members in health and social care voted overwhelmingly in favour of strike action.
Of the 23% of Unison members who took part in the ballot, 92% voted in favour of striking.
The latest development comes after the Royal College of Nursing (RCN) in Northern Ireland announced that 92% of respondents to its ballot had voted in favour of strike action. The vote turnout was 43.3%.
It could mean tens of thousands of NHS workers across Northern Ireland staging walk-outs in the coming months.
Unison is the largest health and social services union in Northern Ireland representing around 25,000 staff, and its membership is made up of all health workers with the exception of doctors, with its largest membership coming from nursing, social care and support services.
The union said that the ballot was focused on the main issues of safe staffing levels and pay justice and that these had been a key factor in the "crisis level" in waiting lists and waiting times for patients in Northern Ireland.
Eight months of pay talks with the Department of Health broke down without agreement.
Union representatives are set to meet on Friday November 15 to finalise plans for what they called "comprehensive industrial action".
It will include strike action and other forms of industrial action across the system and Unison said that they anticipate the first action to take place before the end of November 2019.
Unison Regional Secretary Patricia McKeown said that the decision had not been taken lightly, but that staff had been "pushed to the brink".
She said that members were no longer prepared to accept the lowest pay levels in the UK, the greatest number of frontline vacancies and the highest waiting lists.
Mrs McKeown said the responsibility for the situation lied with the Department of Health, the Head of the Northern Ireland Civil Service David Sterling and the Department of Finance.
"They must access the funding necessary to resolve the pay problem and begin to address safe staffing levels as a matter of extreme urgency," she said.
"Their current proposals are rejected by us as wholly inadequate”
A Department of Health spokesperson said that they remained focused on finding a way forward and were currently finalising a formal pay offer for 2019/20.
"This will be the best offer possible within the budget available, but the reality is that our ability to address pay issues is inevitably constrained at a time of intense budgetary pressures for health and social care services," the spokesperson said.
"These budgetary pressures are clear for all to see, and we have been highlighting these for some considerable time.
"Despite claims to the contrary, there is no separate or untapped source of funding that we can access – nor can money simply be found in the budget.
"As with any other item of expenditure, pay costs come out of the one health budget, which is currently overcommitted. Every pound spent on one priority area is a pound not available for another."