Almost nine in 10 nurses do not believe that the NHS is coping with demand for services, a new poll has found.
Just 12% of nurses from across the UK believe that the health service is currently able to meet demand, according to a major poll of 10,000 nurses.
Meanwhile a third of nurses believe the NHS needs "serious improvement".
The survey also highlights nurses' concerns over the rising number of elderly patients in need of care alongside struggles to find hospital beds because of heightened demand.
Three-quarters said NHS finances had worsened during their career and 30% identified staff shortages as the biggest problem facing the profession's future.
One nurse who was questioned said: "We are constantly being told to reduce cost, and our services are constantly being 'squeezed'. But how much more can we take away from an already failing service?"
Another added: "The NHS is working beyond its capacity and cannot continue to function like this. It is being managed in a reactive away and this is tearing it apart."
The survey comes ahead of the Royal College of Nursing's (RCN) annual congress in Glasgow. Leading nurses will debate serious issues facing the workforce and plan to reiterate calls for the Government to invest in the nursing workforce to meet rising demand.
Janet Davies, RCN chief executive and general secretary, said: "It's a tribute to the quality of health care that people in the UK are living longer, but services need to adapt to meet this heightened demand and at the moment they simply haven't got the resources to do so.
"Nursing staff are already feeling the impact of an ageing population and it is simply not sustainable to have the same number of staff caring for increasing numbers of patients.
"The NHS's financial pressures are very real and can't be ignored. A concerted effort to put nursing at the heart of new models of care, as well as providing adequate social care, will go a long way towards helping it to meet demand.
"The nursing workforce also needs to be given the tools and opportunity to adapt to the nation's changing care needs. It's not just about having more nurses, but having the right specialist nurses in the right settings.
"Our members experience the issues of the health service first hand, and their concerns need to be heard. Modern health care is complex and only by investing in the nursing workforce can we truly ensure that patients of every age get the treatment and care they deserve."
A Department of Health spokesman said: "NHS staff are our greatest asset - that's why there are already 10,800 more nurses on our wards since 2010, as well as 50,000 nurses in training for the future.
"The NHS is busy, but performing well - with 1.6 million more operations taking place each year compared to 2010. We are committed to delivering a safer seven-day NHS and have funded the NHS own plan for the future with an extra £10 billion per year by 2020 to transform services."