The NHS in England has run up a net deficit of £512m in 2005-06, unaudited accounts have revealed.
The government stresses that many organisations have balanced their books.
It says 70% of debt is concentrated in just 11% of organisations.
However, critics fear the NHS faces a serious financial problem.
DR IAN WILSON
British Medical Association's Consultants' Committee
"People should not panic, but they should be very, very concerned.
"Figures like this aren't disposed of easily, and for every pound being spent on trying to reduce deficits, that is one pound less being spent on direct patient care.
"We have to recognise that a lot of money has gone into the health service, and a lot has improved.
"But even more money has been wasted. We are talking about billions and billions of pounds being wasted on management consultancy fees, and on failed attempts to bring in computer systems.
"The debt could be wiped out almost overnight if the government would listen to those that work in the service, and make the changes needed to benefit patients.
"Wouldn't it be wonderful if the government could just let go enough to let doctors and nurses run the health service in a way that is best for patients, rather than in a way that is best for headlines?"
DR GILL MORGAN
Chief executive, NHS Confederation
"The overall NHS deficit announced today represents less than 1% of the overall NHS budget.
"The overall figure hides the patchy distribution of the deficits.
"Whilst transforming the system is challenging to all, the biggest problems are focused in a small number of communities where the problems are long-standing, highly complex and deep-rooted.
"It is all too easy to blame individual managers, but the financial problems often relate to systemic issues.
"Last year's deficit is in part the result of many short-term pressures upon the service including pressure from national policies, such as targets and workforce reforms, which have had an impact on many NHS organisations.
"But some relates to the enormous increases in front-line staff employed by the service.
"Longer-term issues, such as unresolved structural problems which have been exposed by changed to accountancy rules, have also contributed to current difficulties.
"NHS organisations are taking the appropriate actions to reduce the deficits and to re-balance the workforce so that the overspending can be reduced."
Chairman, Patients Association
"I always give credit to the government for the vast amount of income which they have put into the NHS.
"The fault in our view lies with the trusts. The majority of trusts, after all, balance their books, but a minority are failing badly, and this affects patients."
"People are saying to us that they are really concerned.
"These deficits affect ward closures, and there are no more training places for nurses.
"We are very concerned that hospital-acquired infections could increase because there is now going to be a shortage of nurses.
"And, of course, having delayed operations is a great worry to people, particularly the elderly."
Executive director for service delivery, Royal College of Nursing
"The NHS is doing more without a doubt, and nurses have been at the forefront, leading change and delivering results.
"Trusts need time and flexibility to manage their finances, so that patients get the service they deserve and nursing jobs are not lost.
"But bed occupancy rates are increasing, and ward staffing levels are unchanged since 2001.
"We cannot ask nurses to do even more with less.
"The key issue is not how big trust deficits are, it's what they are doing to balance the books.
"We know many are delaying treatments and operations, freezing and deleting posts, downgrading staff and many newly qualified nurses cannot find a job.
"We also know that voluntary and compulsory redundancies are happening or being planned."
Head of health, Unison
"Insisting on a one-year turnaround will lead to a knee-jerk reaction resulting in more services being cut, wards closed and jobs lost.
"The extra investment into the NHS has delivered shorter waiting times and better patient care, but the continuing marketisation of the NHS is undermining progress, and leads to fragmentation as well as destabilising the service.
"Payment by results, the Private Finance Initiative and the constant fog of reform are all fuelling NHS deficits.
"When you add in the £4bn that the Independent Treatment Centres programme will cost over the next five we have a recipe for disaster.
"It is time for the government to take stock review what works and what doesn't and consult with front-line workers who are the drivers of change."
Chief executive, independent think-tank The King's Fund
"These figures mask the true scale of financial problems in the health service.
"The gross deficit has increased throughout the NHS to £1.27bn and has been reduced to a net of £512m only by using increased surpluses from other parts of the service.
"In fact, more NHS organisations are in deficit than predicted, while the net deficits for primary care trusts and hospitals are worse than last year.
"It is especially worrying that trusts have known for months that they have been running an overspend - yet even though they have been under enormous pressure they haven't managed to tackle this.
"Some will certainly need more time but the requirement to manage a budget that already assumes efficiency savings as well as rising cost pressures such as pay deals, new drugs and other technological costs will also add to the challenge.
"But it is important to keep all this in perspective.
"There are serious questions about how some of the extra money going into the health service has been used up - not least in large pay awards - but it has also led to real achievements in reduced waiting times, better cancer services and treatment of coronary heart disease."
Chief executive, Diabetes UK
"The biggest concern about the financial problems in the NHS has to be the fact that patient care is suffering as a result of cutbacks.
"Conditions such as diabetes, where long term treatment and support are key, seem to be at the frontline of these cuts.
"A failure to provide the right care now puts people's long term health at risk.
"If that happens the budget deficits of the future will make today's announcement look like small change."