Paramedics are to join transport workers in Northern Ireland in a 24-hour strike on the eve of the General Election.
Ambulance service members of Unite the union will walk out on May 6 in a dispute over pay and proposed NHS closures.
Train and bus drivers have already said they will take industrial action.
Unite officer Kevin McAdam said: “This fight is about protecting jobs and services and we will do what it takes to get the Stormont mandarins to start treating the staff in health with respect and dignity.
“Our members are the lynch-pin of the NHS and are being treated abysmally when it comes to pay.”
He said the union had agreed action in pursuit of an outstanding pay claim for 2014/15, the lack of an offer for the current year and proposed closures.
“Unite ambulance service members will join Translink workers on 6 May for a 24-hour stoppage from midnight. Other Unite workers across the service will commence a refusal to work unpaid overtime from April 30 to May 10.
“This action is the next stage in our long running pay campaign. We are now joining other health unions in a strategy of varied actions designed to maximise disruption to the management of services while minimising impact on clients.”
All Ulsterbus, Metro and NI Railways services will be affected by a May 6 protest against cuts to public transport.
Unite has said the elderly and infirm who depend upon buses and trains would be hurt by reductions to services by provider Translink.
The union estimates that the cuts to bus and rail services will save only £6-£7 million - which it described as a meagre sum in terms of the wider budget.
It said reductions were being proposed to hospital runs, shopping services, rural routes and town centre buses as well as to morning, evening and Saturday rail services on the Larne-Belfast and Newry-Bangor lines.
Translink has said it is committed to delivering efficiencies which have minimal impact on front line services.