NHS operations and appointments are set to be cancelled after a historic vote by nurses to strike over pay.
The Royal College of Nursing (RCN) said its members in the majority of NHS employers across the UK had backed industrial action.
Industrial action is expected to be held before the end of the year at some of the country’s biggest hospitals, including Guy’s and St Thomas’ opposite Parliament, the Royal Infirmary in Edinburgh, University Hospital Wales and Belfast’s Royal Victoria.
Some of the most serious cancer cases could still be treated, while urgent diagnostic procedures and assessments will be staffed if they are needed to gather data on potentially life-threatening conditions or those that could lead to permanent disability.
Other health worker unions including Unison and the GMB will announce the result of strike ballots before the end of the month among staff including ambulance drivers and paramedics, hospital porters and cleaners.
Physiotherapists started voting on Monday over industrial action, while a ballot of midwives opens on Friday.
The unions are protesting over a pay award earlier this year of £1,400 for most NHS workers, with the RCN calling for a rise of 5% above the rate of inflation.
“Ministers must look in the mirror and ask how long they will put nursing staff through this.
“This action will be as much for patients as it is for nurses.”
Health and Social Care Secretary Steve Barclay said the Government had accepted recommendations from the independent Pay Review Body, adding: “Our priority is keeping patients safe during any strikes.
“The NHS has tried and tested plans in place to minimise disruption and ensure emergency services continue to operate.”
The RCN ballot was the first national one on industrial action in its 106-year history.
Unison’s head of health Sara Gorton said the result was a “loud wake up call” to the Government, adding: “Hundreds of thousands more nurses, paramedics, cleaners, health care assistants and other NHS employees are still to decide if they’ll be striking for better pay and staffing. Now is the time for swift action to avoid a damaging dispute.”
The BMA said doctors offered their support to the nurses, who had borne the brunt of an “under-staffed and under resourced” health service.
NHS Providers said their priority now was to ensure the safe delivery of care and services for patients during any industrial action.
The RCN said industrial action will take place in NHS trusts or health boards where legal requirements to strike have been met.
Many of the biggest hospitals in England will see action by RCN members but other sites narrowly missed the legal turnout thresholds to qualify for action.
All NHS employers in Northern Ireland and Scotland will be included and all bar one in Wales met the relevant legal threshold.
Wes Streeting, shadow health secretary, said: “Government ministers spent the summer dodging calls and requests for meetings from the Royal College of Nursing. It is unacceptable negligence.
“The Conservatives have stopped governing and it is nurses and patients who will be made to pay the price.”
Helen Whyley, director of RCN Wales, said: “Today is a historic day for the nursing profession, our patients, and the future of nursing but ultimately one born of desperation.”