Health and social service workers in Northern Ireland have served notice of industrial action over staffing numbers and pay disputes.
The first phase will run from 25 November till 18 December and phase two will run to March 2020.
Unison, which represents health workers, said members across the entire health and social services system will take part.
The industrial action will also include:
- Not working overtime
- Not working unpaid hours
- Not completing paperwork other than individual patient records
Unison represents about 25,000 healthcare workers including nurses, social care staff, support services but not doctors.
Its membership was asked to vote on a strike over pay and safe staffing levels. The turnout was 23%.
There are 2,484 registered nurses and 454 nursing support worker vacancies in Northern Ireland, according to the latest available statistics, which were published in June.
The union said that none of the workers involved have taken the decision to strike lightly.
"They are determined to fight for justice on both pay and staffing levels," said UNISON regional secretary Patricia McKeown.
"They are determined to break the cycle of hundreds of millions of pounds haemorrhaging out of the health budget and into the hands of private agencies."