More than 30,000 NHS jobs are at risk of being cut, the Royal College of Nursing (RCN) has warned.
Since the coalition came to power in May 2010, the NHS workforce in England has decreased by 28,500 posts, and a further 32,700 jobs are at risk, said the RCN. Between May 2010 and July this year, the number of qualified nurses working for the health service reduced by more than 6,000.
The RCN warned that the NHS is "sleepwalking into a crisis", saying that reduction of staff comes as there is a soaring demand for care. The ageing population and the increasing number of people living with long-term conditions mean that demand for services continues to rise.
"The RCN believes that the NHS is sleepwalking into a nursing crisis in England that is drawing closer as the size of the cuts increase," said a report for the organisation's Frontline First campaign.
"If the Government continues on its current path it will find itself stranded in a perfect storm of an ageing population with increasing healthcare demands, but without the adequate nursing workforce to deal with it."
While NHS trusts locally make the decisions about staffing levels, the RCN said there is a lack of national oversight about the reduction in staff numbers. The organisation is calling on ministers to prevent NHS trusts from "continuing with this damaging agenda of cuts" that "impact on patient care".
Dr Peter Carter, chief executive and general secretary of the RCN, added: "On a daily basis, nurses are telling us that they do not have enough staff to deliver good quality care. Demand for services is continuing to rise. However, staffing levels are being slashed.
"The £3 billion that the Treasury has clawed back from the NHS in the last two years should be reinvested back into vital jobs and services, for example in community provision, that would ultimately improve patient care."
Health minister Dan Poulter said: "NHS performance is strong - waiting times and infection rates are at record low levels. To say that the NHS is in crisis is scaremongering and doesn't reflect reality.
"This Government fully supports the NHS and will put an extra £12.5 billion into the health services by 2015. But at the same time, the health service is changing - average lengths of stay in hospitals are about one third shorter than they were 10 years ago, and there is more surgery where patients don't have to stay overnight on a ward. The numbers of patients treated as day cases is 500,000 more than it was two years ago."