NHS trusts in debt double in year
The number of NHS trusts in debt in England has more than doubled in a year - although overall the health service finished 2011-12 in surplus.
The Audit Commission report said 31 trusts posted a deficit - more than one in 10 of the hospital, mental health and community trusts in the NHS.
The figure is up from 13 the year before.
However, overall the health service posted a £2bn surplus - about 2% of its budget.
The development comes amid an unprecedented savings drive.
Squeeze on finances
The health service has been told to save £20bn by 2015 - the equivalent of 4% a year.
This has never been done before in the history of the health service.
Prof John Appleby, chief economist at the King's Fund, said: "It seems like the squeeze is tipping trusts over into deficit. The chances are this will get worse in the coming years."
The Audit Commission report revealed "stark differences" in health finances around the country with the majority of the deficits focused in London and the south-east.
The trust with the highest deficit was South London Healthcare, which posted a £65.1m deficit. It has been put into administration because of its long-standing problems.
Andy McKeon, of the Audit Commission, said: "While nationally the NHS appears to be managing well financially and preparing itself for the changes and challenges ahead, a number of PCTs and trusts are facing severe financial problems.
"The Department of Health and other relevant national authorities need to focus their attention on the minority of organisations whose financial position is deteriorating."
A Department of Health spokesman acknowledged there were pressures in the health service, but said services were still being maintained.
"The NHS is delivering great results for patients. Waiting times have been kept low, infections have been reduced, there are more doctors, more diagnostic tests and more planned operations."