Nurses in Wales will start voting next month on whether to strike over a planned pay increase.
The potential action is being described as a “defining moment” for the profession and the NHS in Wales.
The Royal College of Nursing (RCN) said it will be recommending its members support industrial action in a ballot that opens in mid-September.
If the strike action goes ahead, it will be the first time members of the RCN in Wales have ever taken part in industrial action.
The postal ballot will open on Thursday, September 15 for four weeks.
The potential action follows the Welsh Government's announcement of a pay award of £1,400 for all NHS pay bands, the equivalent of 4%.
The RCN says this leaves an experienced nurse over £1,000 worse off in real terms.
The union has instead called for a fully funded pay rise for nursing staff of 5% above inflation, which is currently 11.8%.
After the announcement, RCN Wales described the pay award as ‘pitiful and insulting’ to the nursing profession working in the NHS.
Helen Whyley, director of the Royal College of Nursing Wales, said: “The College doesn’t take this lightly. Industrial action should always be a last resort. Our members are telling us that the cost of living is making them seriously reconsider staying in a profession that they love.
"In addition, we are the middle of a nurse staffing shortage in Wales which is putting patients at risk and adding pressure to an already overworked and overstretched nursing profession.
"Nursing staff are exhausted, yet they continue to go above and beyond, providing the best care they can for their patients, every single day. Without the incredible work of nursing staff, patients wouldn’t get the care they need. The time for talk is over.”
A recent survey by the union found that 85% of the public in Wales support a pay rise for nursing staff.
Richard Jones, RCN Wales Board chair, said: “To say that this pay award is well below our expectations is an understatement.
"This does absolutely nothing to recruit and retain nursing professionals. How can the Welsh Government say that they value nursing when we have members living on the poverty line? It’s not acceptable. I’ve been a nurse for more than 50 years and I’ve never seen it this bad.
"The writing is on the wall. We have repeatedly asked our government to address staff shortages, fair pay, flexible working conditions and continuing professional development. Enough is enough.”
Wales' health minister Eluned Morgan has previously said: "We don't want to see industrial action, that would be problematic for us. But people have a right to strike.
"We would have liked to have gone further but we have not had any additional pay from the UK government to support these pay rises."
Both the Welsh Conservatives and Plaid Cymru have also attacked the Welsh Government over its pay increase plans.
The Welsh Conservatives' shadow finance minister Peter Fox said: "It’s taken the Labour Government till the end of the week to make up their minds on what to do – keeping our NHS workers in limbo, whilst Labour pick political fights with the UK Government.
"Whilst I welcome that NHS pay is being increased in line with the recommendations from the independent panel, the Labour Government has been guaranteed an additional £2.5 billion a year in their budgets.
"It’s a shame that the Welsh Government are choosing the wrong priorities such as wasting money on buying up farms, more politicians or stifling the Welsh economy with their road building freeze, instead of supporting our Welsh NHS.”
Plaid Cymru's health and care spokesperson Rhun ap Iorwerth said: "Any pay award that is below inflation is a significant pay cut in real terms.
"This will be a bitter blow for healthcare workers who have shown so much dedication during such an unprecedented and challenging time.
"In addition to ensuring that salaries catch-up with today’s living costs, there also needed to be an uplift to make up for a decade and more of cuts.
"The Welsh Government have failed to do that in recent years and now, as the cost-of-living soars, it is our front-line workers who are bearing the brunt."