Around 4,000 health and social care workers in Northern Ireland are set to join a 24-hour strike planned for later this month in a bid for better pay.
Trade union Unite said that 87% of its healthcare workers across Northern Ireland's five trusts and the ambulance service voted to take industrial action over the next two months.
The strike is due to take place on January 26, followed by two 48-hour strikes on February 16 and 17, 23 and 24.
They are the latest group of healthcare workers to join the rolling industrial action taken by healthcare workers at Unison, Nipsa and GMB for better pay.
It comes as Northern Ireland's Chief Scientific Advisor warned that unprecedented hospital pressures are not expected to ease for at least another month. Professor Ian Young told UTV that a predicted rise in Covid-19 and flu infections will add further pressures to the health service.
In December, members of three unions formed picket lines at hospitals and other health service facilities.
Hundreds of appointments and services were also affected before Christmas, after the Royal College of Nursing took part in two 12-hour strikes across Northern Ireland, England and Wales.
"If proof were needed of the determination of NHS workers to fight for a better deal it's here in the 87% vote recorded in the Trusts in Northern Ireland," Unite general secretary Sharon Graham said.
"In the absence of a functioning Stormont Executive, Prime Minister Rishi Sunak needs to show some leadership, bang some heads together, make sure that we can get back to negotiations and offer NHS workers in Northern Ireland a better deal."
Lead regional officer for Unite in health in Northern Ireland, Kevin McAdam, confirmed the union's members would be joining the picket lines with members of other health unions with the first 24-hour action on 26 January.
"Unite's nearly 4,000 health members in Northern Ireland have returned a 87% rejection of the imposition of a below-inflation pay award to health workers in the region," he said.
"In the absence of action to address our members' pay claim, we have been left with no alternative but to notify employers of strike action."
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