Waiting times in emergency wards are rising as unprecedented financial strains on the health service start to bite, a report suggests.
In the last year the number of patients waiting more than four hours in A&E has risen by 19%, according to a King's Fund report. The health service is facing the longest period of financial constraint in its history, the report states.
While it concludes that the NHS is "holding up", it suggests the health service is entering a period of significant risk which could jeopardise progress made in the last decade.
The report, which analyses the state of the health service halfway through the coalition Government's term in office, states that financial pressures on the health service could begin to impact patient care as early as next year. It claims major organisational changes and the loss of experienced managers could leave the NHS in a precarious position. It also highlights the number of trusts which are in financial difficulty.
"The NHS remains in the foothills of what is certain to be the longest period of financial constraint in its history," the report states. "Already there are signs that the impact on patient care could be felt as early as 2013. There is also an increasing number of providers - including foundation trusts and NHS trusts - in financial distress, with some experiencing serious challenges in delivering services of an acceptable quality.
"Meanwhile, the pressures facing social care departments in local authorities are increasing by the day, and the effects are already being felt in parts of the NHS. Leaders at all levels face a huge challenge to sustain the improvements in performance of the past decade.
"Failure to do so creates political risks for the Government, but even greater risks for patients, if the pressures affecting some organisations spread widely and rapidly. The stakes could hardly be higher."
Areas that the report highlights have improved include progress on hospital bugs and steps made to eliminate mixed-sex wards. But the report states there has been a rise in emergency admissions for people with long-term conditions and an increase in the amount of time pensioners spend in hospital after being admitted as an emergency.
Health minister Lord Howe said: "NHS care, particularly for older people, needs to improve. This is a priority for us, and we are clear that the NHS should make significant improvements in these areas. We are giving the NHS an extra £12.5 billion in the meantime, it continues to perform very well.
"As the King's Fund themselves say - waiting times are down, hospital infections are down, and mixed-sex care is at its lowest ever levels. But to keep pace with an ageing population, and more and more patients with long-term diseases, the NHS must change so that patients can get the best treatment and care they need, when they need it. Our reforms will protect the NHS, ensuring it is in the best possible place for the future."